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Abstract:

Surgical devices for stabilizing the heart are disclosed which facilitate
anastomosis under beating heart conditions. Various instruments or
devices may be maneuvered and secured on a retractor device to provide
stabilization of the heart. An instrument mount is provided which is
preferably configured to accept a surgical instrument, such as a tissue
stabilizer, and to allow the instrument to be easily maneuvered to a
desired position and subsequently locked into position with a simple
operation of a single locking actuator. Further disclosed are stabilizer
devices each having at least one surface for contacting the heart and
each being adapted to be mounted to the retractor while having the
ability to be positioned in the desired location against the heart.

Claims:

1-68. (canceled)

69. An apparatus for stabilizing a localized portion of a beating heart,
comprising:a substantially rigid base member having at least one surface
adapted to contact the surface of the heart, a post having a first end
moveably coupled to said base member and a second end having a
ball-shaped member extending therefrom.

70. The apparatus of claim 69, further comprising a delivery stem having a
proximal end and a distal end, said distal end having a socket operably
engaged with said ball-shaped member.

71. The apparatus of claim 69, wherein said delivery stem is substantially
rigid.

72-76. (canceled)

77. An apparatus for stabilizing a localized portion of a beating heart,
comprising:a base member having at least one surface adapted to contact
the surface of the heart, a link member pivotably coupled to said base
member at a predetermined pivot point, said link member having a first
link end spaced a distance away from said pivot point; anda post having a
first post end attached to said first link end and a second post end
having at least a ball shaped member extending therefrom.

78-83. (canceled)

84. A method for stabilizing a portion of a patient's heart, said method
comprising the steps of:providing a stabilizer movably mounted to an
instrument mount assembly, said instrument mount assembly being mounted
on a stable support;manipulating the stabilizer to apply a stabilizing
force to a surface of the heart;fixing a position of said instrument
mount assembly with respect to the stable support; andfixing a position
of said stabilizer, applying the stabilizing force, with respect to said
instrument mount assembly.

85. The method of claim 84, wherein the stable support is a retractor,
said method further comprising grossly positioning said stabilizer by
sliding said instrument mount assembly with respect to said retractor.

86. The method of claim 84, wherein said fixing a position of said
instrument mount assembly is carried out prior to said manipulating the
stabilizer.

87. The method of claim 84, further comprising placing at least one
articulating joint of said instrument mount assembly in an intermediate
position, prior to said fixing a position of said stabilizer, wherein in
said intermediate position, sat at least one articulating joint may still
be moved, under greater resistance than when in a free state, allowing
continued manipulation of said stabilizer.

Description:

FIELD OF THE INVENTION

[0001]The present invention relates generally to surgical instruments, and
more particularly to a surgical instrument mount apparatus and surgical
retractor system useful for positioning and securing a variety of
instruments including tissue stabilizer devices for use during coronary
artery bypass graft surgery.

BACKGROUND OF THE INVENTION

[0002]Diseases of the cardiovascular system affect millions of people each
year and are a leading cause of death throughout the world. The cost to
society from such diseases is enormous both in terms of the number of
lives lost as well as in terms of the costs associated with treating
patients through traditional surgical techniques. A particularly
prevalent form of cardiovascular disease is a reduction in the blood
supply leading to the heart caused by atherosclerosis or other condition
that creates a restriction in blood flow at a critical point in the
cardiovascular system that supplies blood to the heart.

[0003]Treatment of such a blockage or restriction in the blood flow
leading to the heart is, in many cases, treated by a surgical procedure
known as a coronary artery bypass graft (CABG) procedure, more commonly
known as a "heart bypass" operation. In the CABG procedure, the surgeon
"bypasses" the obstruction to restore normal blood flow to the heart
either by attaching an available source vessel to the obstructed target
coronary artery or by removing a portion of a vein or artery from another
part of the body, to use as a graft, and installing the graft between a
point on a source vessel and a point on a target artery.

[0004]To restore the flow of blood to the heart, the CABG procedure
requires that a fluid connection be established between two vessels. This
procedure is known as an "anastomosis." Typically, a source vessel, such
as a source artery with an unobstructed blood flow, i.e., the left
internal mammary artery (LIMA), or a bypass-graft having one to end sewn
to an unobstructed blood source such as the aorta, is sewn to a target
occluded coronary artery, such as the left anterior descending (LAD)
artery or other vessel, that provides blood flow to the muscles of the
heart.

[0005]Although the CABG procedure has become relatively common, the
procedure itself is lengthy and traumatic and can damage the heart, the
cardiovascular system, the central nervous system, and the blood supply
itself. In a conventional CABG procedure, the surgeon makes an incision
down the center of the chest, cuts through the sternum, performs several
other procedures necessary to attach the patient to a heart-lung bypass
machine, cuts off the blood flow to the heart, and then. stops the heart
from beating in order to complete the bypass. The most lengthy and
traumatic surgical procedures are necessary, in part, to connect the
patient to a cardiopulmonary bypass (CPB) machine to continue the
circulation of oxygenated blood to the rest of the body while the bypass
is completed.

[0006]In recent years, a growing number of surgeons have begun performing
CABG procedures using surgical techniques especially developed so that
the CABG procedure could be performed while the heart is still beating.
In such procedures, there is no need for any form of cardiopulmonary
bypass, no need to perform the extensive surgical procedures necessary to
connect the patient to a cardiopulmonary bypass machine, and no need to
stop the heart. As a result, these beating heart procedures are much less
invasive and the entire procedure can typically be achieved through a
small number, typically one or two, comparatively small incisions in the
chest.

[0007]Despite the advantages, the beating-heart CABG procedure is not
universally to practiced, at least in part, because of the difficulty in
performing the necessary surgical procedures using conventional surgical
instruments. For example, it has been difficult for the surgeon to access
the required areas of the heart requiring revascularization. In addition,
the various surgical steps that are required to be performed on the heart
itself are more difficult to perform because the heart muscle continues
to move and contract to pump blood throughout the duration of the
procedure.

[0008]The specific portion of the surgical procedure that creates the
anastomosis in the beating-heart CABG procedure is particularly
difficult. Completion of the anastomosis requires placing a series of
sutures through extremely small vessels on the surface of the heart while
the heart muscle continues to beat. Moreover, the sutures must be
carefully placed to ensure that the source vessel or graft is firmly
attached and will not leak when blood flow through the vessel is
established. In cases where the target coronary artery is temporarily
obstructed, for example, to improve the surgeon's visibility and avoid
excessive blood loss, it is also important that the anastomosis procedure
be performed rapidly to avoid ischemic damage to the heart.

[0009]Further adding to the difficulty of the procedure is the fact that
the working space and visual access are often quite limited. The surgeon
may be working through a small incision in the chest, for example, or may
be viewing the procedure on a video monitor if the site of the surgery is
viewed via surgical scope. The vessel, and particularly the arteriotomy
to which a source vessel is to be anastomosed, may also be very difficult
for the surgeon to see as it may be obscured more or less by layers of
fat or other tissue.

[0010]The beating-heart CABG procedure could be greatly improved if the
heart could be accessed and stabilized during the procedure such that the
motion of the heart, particularly at the site of the anastomosis, is
minimized even though the heart continues to beat and supply blood to the
body. The beating-heart CABG procedure could be-further improved if the
target vessel, and specifically the arteriotomy was presented to the
surgeon in a way that allows sutures to be easily placed.

[0011]In view of the foregoing, it would be desirable to have improved
devices for accessing and effectively stabilizing the beating heart at
the site of the anastomosis. It would be desirable to have a retractor
system that provides unobstructed and organized access to the areas of
the heart requiring revascularization. It would be further desirable to
have a low-profile, a traumatic stabilizing device that stabilizes the
beating heart at the site of the anastomosis and provides a favorable
presentation of the target vessel and the arteriotomy. It would be
further desirable to provide a mount for the stabilizing device, or other
instruments, that allows the stabilizing device to be easily maneuvered
to the desired position and orientation, fixedly secured until the
procedure is completed, and then easily removed from the site of the
anastomosis.

SUMMARY OF THE INVENTION

[0012]The present invention will be generally described for use in
performing CABG surgery, but the invention is not limited thereto, and is
contemplated to be useful for other surgical procedures requiring
surgical instruments to be positioned and secured through an incision
into a patient.

[0013]The present invention involves various aspects of an instrument
mount useful for positioning and securing surgical instruments, for
example, during a CA procedure on a beating heart. One aspect of the
present invention involves a low-profile, flexible, right-angle
instrument mount for maneuvering and securing a wide array of surgical
instruments.

[0014]One aspect of the present invention involves an instrument mount
apparatus for positioning a surgical instrument comprising a mount body
having a base portion moveably coupled at a first articulating joint and
a side portion moveably coupled at a second articulating joint, the first
and second articulating joints being freely moveable when in an unlocked
condition and substantially immovable when in a locked condition which
may be accomplished through manipulation of a single actuator.

[0015]The actuator may include a base post assembled thorough the base
portion and the mount body and interconnected at a first end to a cam
operatively interfacing a contact surface on the mount body, and a tie
pin having a slotted portion which receives the base post. Operation of
the cam draws the base post toward the cam and into a locked position. A
ramped portion of the base post drives the tie pin into the locked
position.

[0016]A grip member may be included, which forms an opening with the side
portion for receiving a surgical instrument. The tie pin may be
connected, at a first end, to the grip member, preferably by a pair of
flexible prongs. Movement of the tie pin to the locked position draws and
locks the grip member against the side portion and also locks the second
articulating joint.

[0017]The tie pin may further be releasably connected to a release button
at a second end, such that pressing of the release button extends the tie
pin and grip member to allow removal of the grip member to exchange
surgical instruments.

[0018]Preferably, the first articulating joint is at an angle relative to
the second articulating joint. The angle between the first and second
articulating joints is typically less than about 130 degrees, more
typically less than 120 degrees. In a preferred embodiment, the angle is
between about 100 degrees and about 45 degrees, most preferably about 90
degrees.

[0019]The articulating joints may be any mechanical configuration which
provides the desired degrees of freedom for maneuvering a surgical
instrument. Preferably, the first articulating joint comprises a
ball-type joint or a ball and socket joint. The ball and socket joint may
comprise a ball-shaped member extending from the base portion and a to
cooperating socket formed within the mount body. The second articulating
joint may preferably comprise a ball and socket joint or a rotational
joint. When the second articulating joint is configured as a rotational
joint, it may comprise a frustoconical member extending from the side
portion and a cooperating frustoconical cavity within the mount body.

[0020]The side portion and the base portion may include a number of other
features or structures connected thereto for a variety of purposes which
take advantage of the movement of the side portion relative to the base
portion provided by the articulating joints. For example, the side
portion may further include a grip member. The side portion and the grip
member may be positioned to form an opening therebetween for receiving a
surgical instrument. The grip member may have an unlocked condition
relative to the side portion wherein the opening allows relatively free
movement of the surgical instrument and a locked condition wherein the
grip member and the side portion are forced together to lock the
instrument against relative movement.

[0021]The base portion may be adapted to cooperatively engage a rail
member. The rail member may generally have a T-shaped cross-section. In a
preferred embodiment, the rail has a top portion and a bottom portion,
the bottom portion having a narrowed region adjacent the top portion
forming first and second tabs on the top portion and the base portion
further comprises first and second hooks adapted to engage the first and
second tabs. Preferably at least one of said hooks is moveable relative
to the other to allow the base portion to lock onto and release from the
first and second tabs. The rail is preferably fixed or otherwise
associated with a sternal or rib retractor.

[0022]Another aspect of the present invention involves an instrument mount
apparatus for positioning and securing a surgical instrument which
includes a mount body having a base portion moveably coupled at a first
articulating joint and a side portion moveably coupled at a second
articulating joint. A post preferably extends through the first
articulating joint along a first axis and has a first end portion
engaging the base portion. A pin preferably extends through the second
articulating joint along a second axis and has an end portion engaging
the side portion and a threaded portion. A knob is may be provided having
an internal bore for receiving at least a portion of the pin, the
internal bore having threads adapted to engage the threaded portion of
the pin. The knob may preferably have a thrust surface associated
therewith adapted to engage and move the post as the knob traverses over
the threaded portion of the pin in response to rotation of the knob.

[0023]Again, the articulating joints may be any mechanical configuration
which provides the desired degrees of freedom for maneuvering a surgical
instrument. Preferably, the first articulating joint comprises a
ball-type joint or a ball and socket joint. The ball and socket joint may
comprise a ball-shaped member extending from the base portion and a
cooperating socket formed within the mount body. The second articulating
joint may to preferably comprise a ball and socket joint or a rotational
joint. When the second articulating joint is configured as a rotational
joint, it may comprise a frustoconical member extending from the side
portion and a cooperating frustoconical cavity within the mount body.

[0024]The post may preferably further comprises a cam surface positioned
to mate with the thrust surface, whereby rotation of the knob along the
threaded portion causes translation of the thrust surface in a direction
along the second axis, the thrust surface engaging the cam surface to
move the post in a direction generally along the first axis. The knob may
include a first end adapted to be grasped by a user and a housing end
adapted to be received within the mount body. The thrust surface may be
located on the housing end of the knob. In another configuration, the
thrust surface may be provided on a lift member which is slidable along
the second axis. The lift member may have a first end having the thrust
surface and a second end. The housing end of the knob is preferably
positioned to engage the second end of the lift member such that when the
knob is traversed along the second axis, it engages the lift member which
causes the thrust surface to engage the cam surface thus causing the post
to move along the first axis.

[0025]When the post is urged in a first direction along the first axis,
the first articulating joint preferably becomes locked. When the first
articulating joint is a ball and socket joint formed between a ball
extending from the base portion and a socket formed within the mount
body, the ball and socket become locked by operation of the first end of
the post which engages the base portion and forces the two together as
the post is urged upwards. When the post moves in the opposite direction,
the articulating joint returns to a condition which allows relatively
free articulation. A second end of the post is may be constrained within
a top opening provided in the mount body. Preferably, the second end is
slidable within the top opening generally along the first axis.

[0026]These and other features of the present invention will become more
fully apparent from the following description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a perspective view illustrating a cardiac surgery system
according to the principles of the present invention.

[0028]FIG. 2 is a perspective view illustrating a retractor assembly
according to the principles of the present invention.

[0033]FIG. 7 is a top plan view illustrating a preferred platform blade
and retractor drive assembly in an unengaged position.

[0034]FIG. 8 is a top view in partial cross-section illustrating the
platform blade and retractor drive assembly in an engaged position.

[0035]FIG. 9 is a cross-sectional view taken along line 9-9 shown in FIG.
8.

[0036]FIG. 10 is a partial top view illustrating a preferred suture stay
arrangement associated with a platform blade.

[0037]FIGS. 11A, 11B, and 11C illustrate a preferred platform blade latch.
FIGS. 11A and 11B are top and front plan views, respectively. FIG. 11C is
a cross-sectional view 10 taken along line 11C-11C as shown in FIG. 11B.

[0038]FIG. 12 is a perspective view showing a preferred suture lock.

[0039]FIG. 13 is a perspective view illustrating an instrument mount
assembly according to the principles of the present invention.

[0040]FIG. 14 is an exploded assembly illustration of the instrument mount
assembly of FIG. 13.

[0041]FIGS. 15A and 15B are perspective views illustrating the assembly of
the mount cam to the mount base.

[0042]FIGS. 16A and 16B are top and front plan views, respectively,
illustrating a preferred mount cam.

[0078]FIG. 52 is a front perspective exploded view of a stabilizer base
assembly having an adjustable ball/post position.

[0079]FIG. 53 is a rear perspective view of the stabilizer base of FIG.
52.

[0080]FIGS. 54A and 54B are front and rear perspective views of the
stabilizer base assembly of FIG. 52.

[0081]FIG. 55 is a partial cross-sectional view through a portion of the
rear guide slot of the stabilizer base of FIG. 52.

[0082]FIG. 56A is a perspective view of a stabilizer base embodiment
having a single contact member and bail construction.

[0083]FIG. 56B is an end plan view of the stabilizer embodiment of FIG.
56A.

[0084]FIGS. 57A and 57B are perspective views illustrating another
stabilizer base embodiment having a single contact member and bail
construction.

[0085]FIGS. 58 and 59 are perspective views illustrating stabilizer base
embodiments having a single contact member and a bail having a mechanical
drive.

[0086]FIG. 60 is a perspective view of a preferred cardiac surgery system
during operation according to the principles of the present invention.

DETAILED DESCRIPTION

[0087]The present invention involves surgical instruments for accessing
and stabilizing the heart and methods for their use. The present
invention may involve a retractor system or assembly for accessing the
heart. The present invention may also include a mount that allows various
instruments to be easily positioned within the surgical working space,
locked or secured into a desired position for the duration of a
particular surgical procedure, and then easily and safely removed from
the working space. According to a preferred embodiment the instrument may
be a device to facilitate stabilization of the heart during coronary
surgery.

[0088]Although the instruments and methods of the present invention may
have application in both conventional stopped-heart and beating heart
procedures, they are preferably used to access and stabilize the beating
heart during a minimally invasive coronary artery bypass graft (CABG)
operation which has been specially developed to facilitate completion of
an anastomosis, typically between a target artery and a bypass graft or
source artery, without requiring cardiac arrest such as cardioplegia or
fibrillation and without cardiopulmonary bypass (CPB). Further, although
the instruments for accessing and stabilizing the beating heart can be
applied in a number of different surgical contexts involving various
incisions and surgical approaches to the heart as are known in the art,
the instruments and devices described herein are most advantageously
employed in a CABG procedure wherein the heart is accessed through only
one or two minimally invasive incisions in the chest.

[0089]Although the particular source vessel and target artery of the
anastomosis are determined clinically, a common minimally invasive bypass
procedure on the beating heart includes an anastomosis which forms a
connection between the left internal mammary artery (LIMA) as the source
artery, and the left anterior descending artery (LAD) as the target
artery. To complete the anastomosis, the surgeon must dissect a portion
of the LIMA by separating it from the internal chest cavity. Once
dissection of the LIMA is achieved, the surgeon may attach the dissected
LIMA to the target coronary artery, i.e., the LAD by way of creating an
anastomosis.

[0090]In this example, the present invention may involve a number of
discrete components that facilitate access to the anastomosis site, allow
various instruments or devices to be maneuvered and secured in place, and
provide stabilization of the heart. The retractor of the present
invention may be used to provide access to the anastomosis site of the
target artery on the heart itself. The various stabilizer embodiments of
the present invention may be used to stabilize the beating heart during
at least the portion of the procedure during which the surgeon completes
the anastomosis of the LIMA to the LAD. The mount of the present
invention may be used to facilitate convenient manipulation of the
stabilizer, and other instruments or devices, to their desired position
and allows the devices to be secured in that desired position. Although
the LIMA to LAD anastomosis is provided as one example, it is readily
appreciated that the techniques and instruments described herein may be
applied to other procedures depending on the clinical diagnosis and the
patient's anatomy.

[0091]Although each component of the present invention may be used
separately with great benefit, the components are preferably used in
unison to provide a surgical system which provides an unobstructed and
organized surgical field, exceptional instrument maneuverability and
access to the heart facilitating total revascularization of the heart if
required, and effective vessel stabilization during the anastomosis
procedure. Although the present invention will have application whether
access to the heart is achieved by way of a full-sternotomy,
mini-sternotomy, para-sternotomy, thoracotomy or other known to approach,
the exemplar embodiments described below will be generally described with
reference to a coronary artery bypass procedure using a mid-sternal
approach.

[0092]Referring to the figures wherein like numerals indicate like
elements, an exemplar surgical system for performing a mid-sternal
surgical procedure on the beating heart is illustrated in FIG. 1 and
includes retractor assembly 10, mount assembly 20 and stabilizer assembly
30.

[0093]Retractor assembly 10 generally includes a pair of opposing blades
adapted to engage opposite sides of a sternal incision, or other
incision, and a drive mechanism constructed to force the blades, and thus
the sternum apart. Using the drive mechanism, the sternum may be spread
to the desired opening, thus providing the desired access and direct
visualization of the thoracic cavity. If desired, the heart may be
positioned or oriented to best present the target vessels for
anastomosis. This positioning may be established, for example, through
the strategic placement and tensioning of sutures in the pericardial sac,
by appropriately placing the patient in the Trendelenburg position, or by
using a heart positioned in the form or a strap or pad or the like.

[0094]Once the target vessel is in the desired position, at least one
component of stabilizer assembly 30 is brought into contact with the
beating heart adjacent the target site of the anastomosis. The surgeon
then applies a stabilizing force to the beating heart via the stabilizer
assembly 30 which may then be fixed in place, preferably to the retractor
assembly 10 by way of mount assembly 20. The stabilizing force supplied
by the stabilizer assembly substantially eliminates movement of the heart
in the area of the anastomosis so that the surgeon may accurately and
efficiently perform the required anastomosis (or other surgical
procedure). After the anastomosis has been completed, the stabilizing
force is released and the contacting component of stabilizer assembly 30
is removed from the anastomotic site.

[0095]Each of the principal components, the preferred surgical system, and
their methods of use are separately described in detail below. A
preferred retractor according to the principles of the present invention
is described below with reference to FIG. 212. A preferred stabilizer or
instrument mount according to the principles of the present invention is
described below with reference to FIGS. 13-32. Preferred stabilizer
embodiments according to the principles of the present invention are
described below with respect to FIGS. 33-44. A preferred surgical system
and methods for performing a coronary artery bypass on a beating heart
according to the principles of the present invention is described below
with respect to FIG. 45.

[0096]The Retractor

[0097]According to the principles of the present invention, the retractor
generally involves a drive mechanism and a pair of opposing blades
adapted for insertion into an incision and for engaging opposite sides of
the incision. The drive mechanism functions in some manner to urge the
opposing blades apart, thus forcing opposite sides of the incision open
to allow surgical access through the incision. For purposes of performing
a coronary artery bypass, the incision may be any suitable incision which
provides the desired access to the thoracic cavity, and more specifically
a desired area of the heart. For purposes of example only, the retractor
of the present invention will be described with respect to a mid-sternal
incision, however skilled artisans will recognize that many aspects of
the invention are equally applicable to other surgical approaches to the
heart, for example, by way of a thoracotomy, or other suitable access
approach.

[0098]When the heart is accessed by way of an incision through all or a
portion of the sternum, the opposing blades are adapted to be inserted
into and engage opposite sides of a sternal incision such that the
severed sternum may be forced apart by the action of the opposing blades
to create a working space for operating on the heart. Typically, the
drive mechanism is constructed to spread the opposing blades apart in a
generally parallel fashion, however, the parting motion may also have a
significant curvilinear or angular component as well.

[0099]In one embodiment, the blades may be permanently, integrally, or
inseparably formed with a drive mechanism. Preferably however, at least a
portion of the blades are separable from the drive mechanism. That is, at
least some of the features and functions associated with the retractor
blades are allocated to a structural component which is separate,
separable, or otherwise detachable from the drive mechanism. The separate
component and the drive mechanism may be manufactured independently and
then subsequently assembled at the factory or, more preferably, at the
point of use.

[0100]A retractor construction having a separable component allows the
features and functions of the drive mechanism to remain separate from the
remainder of the retractor assembly and vice versa. This allows a greatly
simplified or depopulated drive mechanism and allows the separable
component to have a much more sophisticated construction with increased
features and functionality. Accordingly, the simplified drive mechanism,
which is typically required to be made from a hardened steel, is easier
and more economical to manufacture and easier to maintain, clean and
sterilize post surgically. Moreover, the separate component can be
economically made from materials or processes that allow for the
intricate structural features which provide superior functionality.

[0101]In a preferred embodiment, the drive mechanism is constructed to be
re sterilized and reused a relatively large number of times, and the
feature-rich separate component is constructed to be disposable, i.e.
discarded after a single surgical use. Thus, the depopulated drive
mechanism, which will be used over and over, can afford to be constructed
to be quite robust with a view to materials and manufacturing processes
that will support the rigors of such extended surgical service. The
separable component, free from the typical functional requirements of the
drive mechanism and the service requirements of extended surgical re-use,
may preferably be constructed from any number of engineering materials to
produce an economical component having the desired features and which may
be discarded after a single use if desired.

[0102]In a preferred embodiment, retractor assembly 10 comprises a drive
12 and first and second platform blades 14 and 16 detachably connected to
drive 12, as illustrated in FIG. 2. Preferably first platform blade 14
and second platform blade 16 each have one or more channels or engaging
members 18 adapted to engage opposite sides of an access incision.
Activation of drive 12 forces apart first and second platform blades 14
and 16 thereby causing engaging members 18 to correspondingly force the
incision open to provide access to the desired surgical site.

[0103]In the example of a sternal approach to the heart, engaging members
18 are adapted to engage each side of the incised sternum to reliably
hold and engage the sternum as the sternum is forced open to expose the
thoracic cavity and ultimately the heart. As best seen in FIG. 9, which
illustrates a cross-section of second platform blade 16, engaging member
18 is generally in the form of a channel or the like, preferably having a
U-shape, curved shape, or other shape suitable for engaging the incised
sternum.

[0104]Preferably, engaging member 18 generally has a concave interior
profile 17 for engaging and holding the sternum and a corresponding
convex exterior profile 19 that is relatively smooth so as not to
interfere with other surgical instruments, snag sutures or create other
such difficulties. The engaging members 18 are preferably constructed to
have sufficient strength to withstand the loads required to spread the
sternum yet maintain a suitably low profile to facilitate easy insertion
into the access incision and to require as little space within the
working incision as possible.

[0105]It may be desirable to provide engaging members 18 with features to
reduce trauma to the incision site, increase the traction against the
sides of the incision, or both. A thin pad or layer of non-slip or a
traumatic material (not shown) may be fixed, by way of an adhesive or
other suitable fastening technique, to the interior profile 17 if desired
to reduce slippage and trauma to the severed sternum or surrounding
tissue. Alternatively, the desired features may be integrally fabricated
into engaging members 18. For example, when platform blades 14 and 16 are
injection molded components, traction features such as raised bumps,
ribs, indentations, or the like can be molded integral into engaging
members 18.

[0106]Referring to FIGS. 2-6, drive 12 is preferably constructed to force
the platform blades apart in generally opposite directions. Any type of
drive mechanism which provides the desired separating action of the
blades may be suitable. A common, substantially straight-line parting
motion may be provided by a ratchet or rack arrangement as is generally
known in the art. FIG. 3 illustrates a preferred drive 12 which involves
a bar 15, moveable housing 22 and handle assembly 24 which facilitates
movement of moveable housing 22 relative to bar 15. A first end of first
blade 14 may be operably attached to moveable housing 22 and second blade
16 to bar 15.

[0107]In a preferred embodiment, bar 15 is a substantially rigid bar
having a stationary or fixed housing 21 assembled thereto and thus
forming bar assembly 23. Fixed housing 21 may be fastened to one end of
bar 15 using one or more mechanical fasteners, an interference fit,
suitable adhesive or bonding compounds, welding, or any other suitable
fastening technique. A first end of second blade 16 is preferably
operably attached to fixed housing 21. As with moveable housing 22, fixed
housing 21 may be of any configuration which provides for the structural
attachment of first and second platform blades 14 and 16.

[0108]Bar 15 preferably includes a number of teeth 13 evenly spaced along
at least a portion of its length. Teeth 13 may have substantially
parallel side portions 11 and may have radiused tops 25. The exterior
edges of teeth 13 may be broken or radiused or have a chamfer 26 as
shown. Handle assembly 24 preferably includes a means for engaging teeth
13 so as to drive moveable housing 22 relative to bar 15 to any desired
position under load where it remains so positioned against the load
without need for any applied input or holding force. The means for
engaging teeth 13 could be any suitable gear, ratchet, cog or like
mechanism. Bar 15 may also be adapted and used for receiving an
instrument mount, such as those described in detail below.

[0109]In a preferred embodiment, moveable housing 22 is driven using one
or more drive pins which may successively engage teeth 13 in a cogging
manner. Handle assembly 24 includes drive handle 29 connected to first
and second cylindrical drive bearings 31 and 32. Drive bearing 31
preferably has a raised boss 34 extending from one end to which drive
handle 29 may be pivotally connected by way of pin 33. At the opposite
end, drive bearing 31 has first drive pin 27 and second drive pin 28
extending therefrom and terminating at second drive bearing 32. First and
second drive bearings 31 and 32 are spaced apart a distance 35 which is
selected to be slightly greater than the thickness 38 of bar 15 such that
a portion of bar 15 may be received between first and second drive
bearings 31 and 32. The outside diameters of drive bearings 31 and 32 are
selected so as to fit within guide holes provided in moveable housing 22.
For example, the outside diameter of second drive bearing 32 is sized to
accurately rotate within guide hole 36.

[0110]Moveable housing 22 has a bore 37 extending therethrough for
receiving bar 15. Bore 37 generally has a shape corresponding to the
dimensions of the cross-section of the portion of the bar 15 which is to
pass through bore 36. With handle assembly 24 properly positioned within
the guide holes provided in moveable housing 22, it may be assembled to
bar 15 by placing the end of bar 15 within bore 36 and turning handle 29
such that first and second drive pins 27 and 28 become engaged with teeth
13. Once assembled in this manner, moveable housing 22 may be forced one
way or the other along the length of bar 15 by turning handle 29, and
thus drive bearings 31 and 32, to cause first and second drive pins 27
and 28 to progressively engage teeth 13 along bar 15.

[0111]As mentioned above, first and second platform blades 14 and 16 may
be removably assembled to moveable housing 22 and fixed housing 21,
respectively. Platform blades 14 and 16 may be attached in any suitable
fashion including, for example, threaded connections or other mating
features on the platform blades and housings themselves, ordinary or
specialized mechanical fasteners, and cam or latching mechanisms adapted
to secure the platform blades to the housings. In a preferred embodiment,
both moveable housing 22 and fixed housing 21 are constructed with
features that engage, secure and support first and second platform blades
14 and 16 in an operable position on drive 12, thus providing an
assembled retractor 10 which is ready for surgical use.

[0112]Referring to FIGS. 7 and 8, second platform blade 16 is shown before
and after assembly onto fixed housing 21. Preferably, at least one of the
platform blade 16 or the fixed housing 21 has an extending protuberance,
post or like feature which can be receivably engaged by the other of the
platform blade or housing. In a preferred. embodiment, fixed housing 21
is preferably constructed to have a latch post 42 adapted to be received
within latch post cavity 45 provided in platform blade 16. Latch post 42
may have a hole, notch, protuberance, or other feature formed therein
which may be engaged in any convenient manner by the platform blade 16 so
that platform blade 16 becomes releasably locked in place for use.

[0114]Latch 48 is preferably constructed to engage and disengage latch
post 42 by manual rotation of latch knob 49. Latch body 50 includes
cylindrical portion 55 which provides for controlled rotation within
latch body cavity 56. Latch body 50 may be biased towards the engaged
position shown in FIG. 8 by way of any suitable spring element.
Preferably, latch post 42 is provided with an angled tip 43 having a
lead-in angle 44 which allows angled tip 43 to slide against second
engaging surface 54 as latch post 42 begins to be received within latch
post cavity 45. As latch post 42 is advanced further within latch post
cavity 45, angled tip 43 causes latch 48 to rotate out of the way about
cylindrical portion 55. Near the end of the advancement of latch post 42
within latch post cavity 45, the angled tip is advanced beyond latch body
50, and latch 48 (which is biased towards an engaged position) rotates
into the engaged position with second engaging surface 54 biased against
stop surface 52.

[0115]With latch 48 and latch body 50 snapped into the engaged position,
any separating force encountered between platform blade 16 and fixed
housing 21 is resisted by action of first engaging surface 53 against
latch surface 51. With this configuration, the reaction force at first
engaging surface 53 is advantageously borne by latch body 50 primarily in
compression. Thus, since the loading is primarily compressive in nature,
a high strength material is not required, and latch 48 can be made from
standard engineering polymers, for example, such as polycarbonate.

[0116]When it is desired to remove platform blade 16 from drive 12, the
operator simply turns latch knob 49, causing latch body 50 to be placed
in a disengaged position relative to latch post 42. With latch 48
disengaged, latch post 42 of fixed housing 21 is free to be removed from
latch post cavity 45 of platform blade 16. As is apparent from the
Figures, a mirror image of the latch assembly described with reference to
platform blade 16 and fixed housing 21 is provided to releasably attach
platform blade 14 to moveable housing 22.

[0117]When the retractor assembly is used to gain access to the thoracic
cavity, a good deal of force must be generated to create the desired
opening. For example, a separating force in excess of 100 pounds may be
required to be generated at each engaging member 18 to achieve the
desired separation of a particular sternum. Such loads must be carried by
the engaging members and transmitted to drive 12 by way of platform
blades 14 and 16. Since platform blades are preferably made from a
suitable engineering polymer (for example, a glass filled thermoplastic
polyurethane resin), it may be desirable to provide a reinforcing member
for each of platform blades 14 and 16 to ensure that platform blades 14
and 16 will not break or otherwise rendered inoperable as a result of the
loads encountered during use.

[0118]Although the reinforcing members may be a permanent or removable
members within the platform blades themselves, the reinforcing members
are preferably one or more substantially rigid members extending from
each of the fixed housing 21 and the moveable housing 22. In a preferred
embodiment, fixed and moveable housings 21 and 22 have a pin extending
therefrom which may be received within a mating cavity within first and
second platform blades 14 and 16. The pin operates to spread the load
developed in the mechanism over a larger internal area within the
platform blades 14 and 16 and reduces the effective beam length of
unreinforced platform blade material subjected to the operating loads.
The pin may be straight pin 40 illustrated in FIG. 3. More preferably,
fixed and moveable housings 21 and 22 have tapered pins 40 and platform
blades 14 and 16 have mating tapered cavities 41 for receiving tapered
pins 40. The tapered construction tends to allow the user to easily align
pin 40 with cavity 41 and allows the pins 40 to fit relatively snugly
within cavities 41 without significant binding during insertion that
could otherwise occur between elongate pins and mating cavities which are
designed to be very close fitting.

[0119]To provide sufficient load bearing reinforcement, the reinforcing
pins 40 are preferably constructed of a substantially rigid material,
such as steel, and are preferably at least about 0.75 inches long, more
preferably at least about 1.125 inches long, and most preferably between
about 1.25 inches to about 2.25 inches long. In a preferred embodiment,
reinforcing pins 40 are made from AISI 420 stainless steel having a
length of about 1.5 inches, an outside diameter near the housing of about
0.25 inches, and a 2 degree taper angle decreasing towards the free end
of the reinforcing pins 40.

[0120]In the preferred embodiments just discussed, platform blade 16 can
be removed from drive 12 with a substantially straight-line relative
motion as indicated by arrow 46. This engagement action not only provides
for simple and intuitive assembly in the operating room, but also
represents a significant safety feature. Under certain rare
circumstances, for example where the drive through neglect or misuse has
become sufficiently damaged during use that it is unable to close and
disengage from the sternum, an extremely dangerous situation can be
created for the patient. In such exigent circumstances, the configuration
described above may allow the drive to be separated from the in situ
platform blades by releasing the latches and applying a sufficient amount
of force in the direction indicated by arrow 46. Once the drive has been
removed, the detached platform blades may be easily removed from the
patient.

[0121]In addition to engaging members 18, detachable platform blades 14
and 16 may incorporate a wide variety of additional features which
enhance the performance of the retractor system. For example, one or both
of platform blades 14 and 16 may have mounting features to which various
instruments used during the procedure can be secured. In the case where a
stabilizer is to be secured to a retractor for operating on a beating
heart, it is critical to minimize or substantially eliminate the amount
of flex and motion attributable to each component and each connection
between each component, from the component engaging the beating heart to
the component which provides the sternal attachment. To this end, the
engaging features 18 which engage the sternum are preferably part of a
unitary platform blade structure which also includes mounting features to
which a stabilizer and other instruments can be mounted. Since the
mounting features and the sternal engaging features are part of the same
component, and therefore there is no mechanical connection between the
two, the stability of an attached instrument against the forces of a
beating heart is greatly improved.

[0122]In a preferred embodiment, each of first and second platform blades
14 and 16 include mount features in the form of rails. The rails allow
one or more instruments to be positioned at any desired location along
the operable length of the rail. Preferably, the rails are oriented in a
direction generally perpendicular to the direction of separation, in this
case perpendicular to bar 15. The rails may be a recessed feature within
the body of platform blades 14 and 16. More preferably, the mounting
rails extend upwardly from the body of platform blades 14 and 16.

[0123]Referring to FIGS. 7-9, right platform blade 16 has rail 60
extending over at least a portion of the length of platform blade 16.
Rail 60 may have a top portion and a bottom portion having a narrowed
region adjacent said top portion. In one embodiment, rail 60 preferably
has a T-shaped cross-section. The T-shaped configuration has a top
portion 61 and a narrowed portion 62, thus forming mounting tabs 63 and
64 which can be gripped by a number of appropriately constructed mounts.

[0124]The rail may be straight, curved, or a combination of straight and
curved portions. Preferably, at least a portion of the T-shaped rail is
curved in a manner which more closely follows the profile of the access
or incision site (as seen, for example, see FIG. 45). In a curved rail
configuration, instruments extending perpendicular to a generally central
axis 67 of rail 60 will naturally point more towards a central area
between the platform blades 14 and 16, and thus may require less
positional adjustment or manipulation from their normal, natural or
beginning position. In addition, all or a portion of top portion 61, and
more specifically mounting tabs 63 and 64, may be tilted or angled
inwardly at an angle 65 as shown.

[0125]Platform blade 16 may be also be provided with a number of suture
holders or stays which can be used to organize or capture various sutures
used in the course of a particular surgery. Since certain sutures are
placed near the beginning of a CABG procedure, such as pericardial
sutures used to position the heart, the placement of the suture stays in
a manner which does not interfere with subsequent procedures and
instruments is an important aspect of the present invention. Preferably,
the suture stays are positioned such that placing and manipulating the
sutures or the various instruments and instrument mounts employed during
surgery can be accomplished without interfering with each other.
Preferably, the location of the suture stays position the sutures below
the level of the mounting tab 63 and 64 so that a mating instrument mount
may traverse the entire operable length of rail 60 without interfering
with the sutures.

[0126]Rail 60 may have one or more grooves, channels, slots or passageways
for receiving a suture. In addition, a suture lock may be provided in the
rail or elsewhere on platform blade 16 so that the suture may be fixed in
place. To accommodate the use of pericardial sutures, which are often
subjected to a significant amount of tension when used to position the
heart, the suture locks must be adapted to hold the suture material even
while under a significant amount of tensile loading.

[0127]In a preferred arrangement for organizing and locking sutures, and
in particular tensioned pericardial sutures, rail 60 has at least one
open slot or passageway formed therein for receiving the free end
portions of a surgically placed suture. The passageways preferably extend
across rail 60 and have a depth which allows the suture to lay at an
elevation sufficiently below mounting tabs 63 and 64 so as not to
interfere with an instrument mount sliding along rail 60. In a preferred
embodiment the passageways extend through at least a portion of narrowed
portion 62. Thus, the height 66 of narrowed portion 62 may be selected
not only to provide sufficient space for a desired instrument mount to
attach, but also to ensure that mounting tabs 63 and 64 are sufficiently
raised above the surrounding features of platform blade 16 so that an
instrument mount may be positioned and repositioned along rail 60 without
disturbing or disrupting the sutures within the various passageways.

[0128]The passageways may be a single channel for receiving both free ends
of a surgically placed suture or each end may have a separate channel. In
a preferred embodiment, rail 60 has a number of bifurcated channels 70 at
predetermined intervals along its length. Referring to FIG. 10,
bifurcated channel 70 has a single entrance channel 71 which bifurcates
into first and second exit channels 72 and 73. Entrance channel 71 and
either one of exit channel 72 or 73 can be used in the same manner as a
single channel, with both free ends 76 and 77 being routed together.
Alternatively, both suture ends may be received within entrance channel
71 and then separated, one end within exit channel 72 and one end within
exit channel 73.

[0129]A means for clamping the suture against movement within the suture
channels may be provided on any of entrance channel 71 or exit channels
72 or 73. Preferably, suture locks are provided on each exit channel 72
and 73. This allows the surgeon to positively identify and unlock a
desired suture end for further tension adjustments or other manipulation
without unlocking or loosening the other end of the suture. In addition,
placing each suture end 76 and 77 in separate exit channels 72 and 73,
each with a dedicated suture lock, increases the maximum amount of
tension that can be applied to a given suture. Exit channels 72 and 73
may have recesses 74 and 75, respectively associated therewith for
receiving a suture lock adapted to secure the suture material within the
channels.

[0130]A preferred suture lock 80 is illustrated in FIGS. 10 and 12. Suture
lock 80 has a relatively rigid body 83 having a fixed or pivot end 81
which allows body 83 to pivot within the mating profile of recess 74 or
75. Pivoting the body 83 about pivot end 81 selectively engages and
disengages free end 84 against the wall 78 of exit channel 72 or 1073.
Alternatively, suture lock 80 may be made from a more flexible material
which, by nature of the elastic properties of the material, tends to flex
about its fixed end instead of rotate. In a preferred embodiment, fixed
or pivot end 81 is substantially cylindrical and recesses 74 and 75 have
mating cylindrical surfaces.

[0131]Preferably, the suture lock is angled relative to the wall 78 so
that it is self-locking in one direction. That is, the suture ends 76 or
77 (or both) operate on the free end 84 in such a way as to force it
towards wall 78, and thus against the suture material, in proportion to
the tension, T encountered by suture ends 76 or 77. Thus, within
practical limits, the higher the tension the harder free end 84 will
press or bite against the sutures placed therein. Conversely, when the
suture ends are pulled in the direction indicated by arrow 79, the suture
forces tend to pivot body 83 about pivot 81 such that free end 84 is
rotated away from wall 84 allowing the suture to move relatively freely.
Preferably, angle 79 between body 83 and wall 78 is nominally about 1
degree to about 30 degrees, more preferably about 5 degrees to about 15
degrees, most preferably about 10 degrees. Of course, angle 79 is greater
as body 83 pivots to accept a suture placed within the suture channel.

[0132]Suture lock 80 may be biased towards the locked position, preferably
using a small spring between the suture lock and the recess 75. In a
preferred embodiment, a piece of resilient closed cell foam 85 is fixed
to body 83 to provide the desired biasing effect. Free end 84 may
optionally have a number of teeth or ridges 82 to ensure acceptable
traction against the suture material.

[0133]Platform blades 14 and 16 may also be provided with soft tissue
retainers to help control and retain the incised tissue and fat in the
immediate vicinity of the blades. Referring to FIGS. 8 and 9, platform
blade 16 includes integrally attached tissue retainer 85. Tissue retainer
85 is generally at a small distance 88 above the top of the engaging
members 18. Tissue retainer 85 may be made from a flexible material, such
as an elastomer, preferably a polyurethane elastomer having a durometer
in the range of about 45 to about 75 Shore D, more preferably about 55
Shore D. In a preferred embodiment tissue retainer 85 is injection molded
over the platform blade to form a permanent and inseparable assembly.
Tissue retainer 85 may have a raised outer lip 86 and optionally having a
plurality of slots 87 formed therein to receive and organize any loose
suture ends. Tissue retainer 85 ensures that the tissue surrounding the
access incision does not interfere with the operation of rail 60 or the
suture holders and also provides a convenient location for attaching
surgical drapes of the like without interfering with the operation of the
retractor assembly.

[0134]Although some of the features of the present invention have been
described, for illustration only, with respect to only one of the
platform blades 14 and 16, it should be apparent that both platform
blades 14 and 16 may have similar or identical features. Although not
necessarily so, first platform blade 14 and second platform blade 16 are
preferably substantially mirror images of each other.

[0135]The retractor assembly just described, provides a simplified drive
mechanism for use in conjunction with mufti-featured platform blades. In
addition, a number of different platform blades may be provided for use
with a single drive, for instance, tailored to different sized anatomy or
the specifics of different surgical procedures. Thus, a number of
platform blade configurations can be provided to an operating room and,
based upon pertinent prevailing clinical factors, the proper
configuration can be selected, mounted to drive 12, and used as described
above to provide access to a desired location. Also, with the modular
configuration new features and advancements can be rapidly incorporated
into the platform blades and immediately introduced for use with existing
simplified drives already in place in the operating rooms.

[0136]The platform blades themselves represent a surgical platform that
allows instruments to be mounted and stabilized in virtually any
position, even over already placed and secured sutures from the surgical
site accessed by the retractor assembly. Described below are preferred
instrument mounts for use in conjunction with rail 60 to secure a beating
heart stabilizer or other instruments such as heart positioners, saline
or medical air blowers, suction devices, surgical clamps, or vessel
occluders.

[0137]The Instrument Mount

[0138]Referring to FIG. 13, a preferred instrument mount assembly 20 is
shown for mounting an instrument, such as stabilizer assembly 30, to an
instrument mounting rail such as described above with respect to rail 60
of platform blades 14 and 16. Mount assembly 20 includes mount base 115
having features to secure mount assembly 20 at a desired position on an
appropriately configured mating rail or other suitable structure and
includes a stem locking mechanism for controlling and securing an
instrument delivery stem in a desired position and orientation.

[0139]One important aspect of instrument mount assembly 20 is to provide
the necessary degrees of freedom to allow the instrument to be easily
maneuvered to whatever position may be required by a particular
procedure. As discussed above, an additional aspect with respect to
stabilizing the beating heart is to eliminate or minimize the flex or
motion attributable to the various components and connections of
instrument mount assembly 20. As will be discussed in more detail below,
instrument mount assembly 20 is uniquely suited for use in stabilizing
the beating heart because it allows sufficient degrees of freedom to
easily manipulate the position of an instrument secured thereto, allows
the degrees of freedom to be frozen or locked in place and, once locked
in place, does not significantly flex or allow movement at any of the
articulating or mechanical joints or connections.

[0140]Instrument mount assembly 20 provides a number of different
controllable articulating joints that, when in a released condition,
allows motion in one or more predetermined directions or about one or
more degrees of freedom. Although instrument mount assembly 20 may be
used to secure any mounting delivery stem configuration from straight
substantially rigid shafts to curved substantially rigid tubes to
malleable delivery systems to multi-link or segmented ball and socket
type delivery stems which are relatively flexible until themselves locked
in some manner at each joint along the delivery stem length, it is most
advantageously constructed to provide the joints or connections required
to position an instrument having a straight, substantially rigid shaft or
a curved, substantially rigid tubular member.

[0141]In a preferred embodiment, instrument mount assembly 20 has three
releasable joints or connections for controlling the location and
position of the instrument mount assembly and instrument attached
thereto. The mount base may be positioned at a desired location along an
appropriate rail and secured by rail grips 114 and 116. The position and
orientation of the instrument is then determined by ball joint (or ball
and socket joint) 112 between mount base 125 and mount body 110, a
rotational joint 157 between mount body 110 and stem hub assembly 160,
and a stem clamping mechanism within stem hub assembly 160 which may
allow translation, rotation, or both of delivery stem 3 relative to stem
hub assembly 160.

[0142]Ball joint 112 is preferably of the ball and socket type having 3
rotational degrees of freedom. Rotational joint 157 allows rotation of
stem hub assembly 160 about axis 121 as indicated by arrow 113. The stem
clamping mechanism allows translation of instrument delivery stem 3 as
indicated by arrows 111 as well as rotation about the delivery stem
itself as indicated by arrow 117. As will be discussed later, a further
ball joint-type connection 201 may be employed between delivery stem 3
and the particular end-effector of the instrument.

[0143]Instrument mount assembly 20, having the particular joints and
connections identified above, allows all the required areas of the heart
to be conveniently and intuitively accessed by a stabilizer connected to
one end of a substantially rigid shaft or, more preferably, a curved,
substantially rigid tubular member as shown in FIG. 13, for example.
Certainly, instrument mount assembly 20 could be provided with more or
less degrees of freedom for maneuvering a particular instrument. For
example, to add additional degrees of freedom rotational joint 157 could
be replaced with a ball joint and to eliminate degrees of freedom
delivery stem 3 could be keyed within stem hub assembly 160 or ball joint
112 could be replaced with a rotation only joint. However, it should be
noted that excessive degrees of freedom may tend to make instrument
adjustment increasingly difficult and cumbersome to control while too few
degrees of freedom may not allow the instrument to be easily placed in
the desired position or orientation.

[0144]In one embodiment, the various joints and connections are locked
into a desired position by way of a series of knobs. The degrees freedom
provided by ball joint 112 is locked by activation of top mount knob 120.
Both rotational joint 157 and the stem clamping mechanism of stem hub
assembly 160 is locked in place by the activation of side mount knob 118.
Base 125 is locked in position on the rail by activation of mount lever
122. Ball joint 201, as will be discussed in greater detail below, may be
locked in position by activation of knob 504. This particular sequence of
knobs used to lock down the degrees of freedom associated with instrument
mount assembly 20 tends to allow the user greater precision in
positioning the instrument because degrees of freedom unnecessary to a
particular desired maneuver of the instrument can be locked down. Most
commonly, mount body 110 is placed at a desired angle or orientation and
then fixed in place by locking ball joint 112, leaving final adjustment
to take place using rotational joint 157 and the delivery stem movement
allowed by the stem clamping mechanism of stem hub assembly 160.

[0145]FIGS. 14-20 show in greater detail the various mechanisms which lock
and release the joints or connections associated with instrument mount
assembly 20. FIG. 20 14 shows an exploded assembly illustration of
instrument mount assembly 20. Instrument mount assembly 20, and more
specifically mount base 125 to which all the other components are
ultimately secured, is preferably constructed to engage and lock in
position on a rail or other suitable feature.

[0147]Hinge member 115 may be articulated using any suitable mechanism
capable of pivoting hinge member 115 to a closed position and holding it
there. In a preferred embodiment, best illustrated in FIGS. 15A-17, hinge
member 115 includes follower .surface 155 which may be acted upon by any
suitable cam device to drive hinge member 115 about hinge pins 123 and
124, thus urging rail grip 116 towards rail grip 114.

[0149]The varying radius of cam surface 152 may be configured to place
hinge member 115, and thus rail grip 116 in a variety of positions. A
first portion of cam surface 1525 may be configured such that follower
surface 155 biased against cam surface 152 is placed in an position
characterized in that rail grip 116 is sufficiently spaced apart relative
to rail grip 114 to allow assembly onto a rail or other structure. A
second portion of cam surface 152 has an increasing radius such that
rotation of cam 145 moves rail grip 116 towards rail grip 114 to an
intermediate position. In the intermediate position, rail grip to 116 has
been moved close enough to rail grip 114 so that it becomes captured on a
rail but remains loose enough to slide along the rail. A third portion of
cam surface 152 has an increasing radius such that the rotation of cam
145 moves rail grip 116 further towards rail grip 114 to a completely
locked position wherein relative motion between rail grips 114, 116 and
the rail is essentially no longer possible.

[0150]Cam 145 is generally provided with a handle or lever 122 to allow
the user to easily turn cam 145 relative to mount base 125. Cam 145 may
be captured onto mount base 125 by operation of retaining hook 150 on cam
145 which rides within exterior groove 151 on mount base 125 on one side,
and projection 154 which is engaged below undercut 156 generally opposite
to retaining hook 150. Projection 154 also serves to work against
undercut 156 to return hinge member 115 to the open position as cam 145
is rotated in the opposite (open) direction. Hinge member 115 preferably
has first and second end stops 158 and 159 between which the motion of
projection 154 (and thus the rotation of cam 145) is limited. Cam 145 may
also have a protective extended portion or cover 163 which shields the
area of groove 151 when assembled over mount base 125.

[0151]The assembly of cam 145 and hinge member 115 to mount base 125 is
illustrated in FIGS. 15A and 15B. Cam 145 is placed in position relative
to hinge member 115 with projection 154 in place below undercut 156. In
roughly that position, cam 145 and hinge member 115 are brought over
mount base 125 until bore 127 is properly seated over cam guide 153 and
retaining hook 150 is positioned within groove 151. Pins 123 and 124 are
then pressed in place through holes provided in both mount base 125 and
hinge member 115.

[0152]Ball joint 112 is generally created between ball 129 provided at the
top of mount base 125 and a socket or mating cavity within mount body 110
adapted to receive at least a portion of ball 129. Preferably ball 129
includes a generally spherical portion, although other curved shapes
providing the desired degrees of freedom may also be suitable. Base post
130 extends vertically upward through bore 126 of mount base 125 and
vertical passageway 128 of mount body 110 until enlarged end portion 130
become biased against mount base 125. Top mount knob 120 may then be
threaded onto threaded shaft 132 whereby mount base 125 and mount body
110, with ball 129 received within mount base 125, becomes captured
between top mount knob 120 and enlarged end portion 130. Continued
tightening of top mount knob 120 over threaded shaft 132 forces ball 129
harder against mount body 110 until the friction between mating surfaces
on ball 129 and mount body 110 become so great as to effectively resist
any relative movement, thus locking ball joint 112.

[0153]The assembly of rotational joint 157 and stem hub assembly 160 are
shown in FIG. 19. Rotational joint 157 is in the form of a conical clutch
formed between frustoconical surface 138 of clutch member 135 and mating
frustoconical surface 139 in mount body 110. Stem hub assembly 160 is
generally formed as upper and lower stem locks 136 and 137 are advanced
over stem grip 140 and against instrument delivery stem 3 which is
positioned between stem locks 136 and 137 and outer stem guide 144. As
clutch member 135 is received over the outside diameter of grip housing
141 of stem grip 140 tang 164 becomes engaged between upper stem lock 136
and lower stem lock 137 thereby preventing relative rotation between
clutch member 135 and stem grip 140.

[0154]Side mount knob 118 having threaded shaft 119 extends through mount
body 110 (and consequently through transverse bore 131 in central portion
167 of base post 130), clutch member 135 and into interior threads 142
within grip housing 141 of stem grip 140. Tightening of side mount knob
118 clamps the assembly together. Thus, translation and rotation of
instrument delivery stem 3 is prevented as stem grip 140 and clutch
member 135 are forced together to clamp or trap instrument delivery stem
3 between stein locks 136 and 137 and outer stem guide 144. Also,
relative rotation between frustoconical surface 138 of clutch member 135
and mating frustoconical surface 139 in mount body 110 is prevented as
clutch member 135 is forced against mount body 110. One or both of
frustoconical surface 138 and mating frustoconical surface 139 may
include a number of teeth, ridges, or other features to prevent rotation
when clutch member 135 is forced against mount body 110.

[0155]So that the delivery stem does not become too loose as side mount
knob 118 is loosened, a minimum amount of friction between instrument
delivery stem 3 and the clamping surfaces 146 of outer stem guide 144 is
preferably maintained by providing a biasing load against delivery stem
3. Referring to FIG. 20, stem biasing member 147 is provided within stem
grip 140 to maintain a biasing load against delivery stem 3. Stem biasing
member 147 has a first portion 148 which slides within counterbore 143 in
stem grip 140. Stem biasing member 147 may optionally have a second
portion 149 having external dimensions sized to be received within the
inside diameter of compression spring 133. Compression spring 133 urges
end 134 of stem biasing member 147 against delivery stem 3 to force
delivery stem 3 against clamping surfaces 146. The amount of force is
selected to allow instrument delivery stem 3 to be easily positioned by
hand but would generally not allow instrument delivery stem 3 to slide
relative to stem grip 140 under only its own weight.

[0156]Referring to FIG. 21 a preferred instrument mount assembly 20 is
shown fixed to a preferred platform blade 16 having rail 60. As discussed
above, rail 60 has mounting tabs 63 and 64 over which rail grips 114 and
116 may be secured. Instrument mount assembly 20 can be positioned,
maneuvered, and removed virtually anywhere along rail 60 without
disturbing suture 166 locked in place by free end 84 of suture lock 80
below the operating features of instrument mount assembly 20 within any
one of the suture channels provided in platform blade 16. In addition,
rail 60 is placed in close proximity to engaging member 18 and thus close
to the surgical opening into the patient providing a more direct access
to the heart by an instrument mounted to instrument mount assembly 20.
Since the rail 60 moves in unison with platform blade 16, this
relationship between rail 60 and engaging member 18 is maintained no
matter how much or how little platform blades 14 and 16 have been spread
to create the desired surgical opening.

[0157]FIGS. 22A-32 illustrate a preferred embodiment of an alternative
instrument mount assembly 220. Preferably, the degrees of freedom
available for maneuvering instrument mount 220 is substantially the same
as that of instrument mount assembly 20. Instrument mount assembly 220
preferably has ball joint 112 between mount base 221 and mount body 222,
a rotational joint 157 between mount body 222, and a stem hub assembly
227 which allows rotation and translation of an instrument delivery stem
held between stem grip 226 and clutch member 226 of stem hub assembly
227. Instrument mount assembly 220, however, has a different mechanism
for controlling or locking the various joints and connections and may
also provide a means for releasing and removing the delivery stem from
the bulk of the remainder of instrument mount assembly 220.

[0158]As just mentioned, the joints and connections themselves are quite
similar between instrument mount assemblies 20 and 220. As before, ball
joint 112 is a ball and socket configuration created between generally
spherical ball 224 provided at the top of mount base 221 and a mating
cavity within mount body 222 adapted to receive and slide against at
least a portion of ball 224. Rotational joint 157 may be in the form of a
conical clutch formed between frustoconical surface 243 of clutch member
225 and mating frustoconical surface 244 in mount body 222. An instrument
delivery stem may be clamped in place within stem hub assembly 227 by
forcing together stem grip 226 and clutch member 225 thus closing clamp
surface 239 of outer stem guide 233 towards V-shaped channels 273 on stem
locks 231 and 232.

[0159]Instead of locking the joints and connections by way of multiple
knobs as described above with respect to instrument mount assembly 20,
instrument mount assembly 220 preferably uses a mechanism which releases
each of ball joint 112, rotational joint 157, and the stem clamping
mechanism of stem hub assembly 227 by activation of a single knob, lever,
or other suitable manual interface. Generally speaking, this is
accomplished by utilizing the clamping motion required to lock one or
more of the joints or connections along a first axis to also lock the
remainder of the joints or connections along remaining axes.

[0160]In a preferred embodiment, ball 224 of mount base 221 is locked in
place relative to housing 222 by operation of base post 230. Base post
230 is assembled trough mount base 221 and mount body 222 from the bottom
until bottom flange 259 (see FIG. 27) is resisted against mount base 221.
At the top of base post 230 is upper link portion 256 having pivot hole
257. Cam 235 is attached through pivot hole 257 at off-center link pivot
238 using a pin or other suitable fastener and is supported by contact
surface 236 associated with mount body 222. Contact surface 236 may be an
integral feature of mount body 222 or may be in a separate mount body
cover 254 which may be selected to have superior wear characteristics.

[0161]With cam 235 in a closed position, as shown in FIG. 24, link pivot
238 is drawn to its maximum distance 251 (or slightly less than the
maximum if the cant is constructed to rotate over center) from contact
surface 236 thus increasing the clamping force between mount body 222 and
ball 224 as the assembly is clamped between cam 235 on the top and bottom
flange 259 on the bottom. With cam 235 in the closed position, ball joint
112 is effectively locked.

[0162]By rotating cam 235, by way of handle 237, to an open position as
illustrated in FIG. 25, link pivot 238 is withdrawn to a position closer
to contact surface 236 at a distance 252, thus reducing or relaxing the
clamping forces between mount body 222 and 096 ball 224 of mount base
221. With cant 235 in the open position, the friction at ball 224 is
reduced to a level that allows the user to easily manipulate mount body
222 relative to mount base 221.

[0164]That same motion of base post 230, created by operation of cam 235,
is preferably also used to lock both rotational joint 157 and the
instrument stem clamping mechanism of stem hub assembly 227. Instead of
using a threaded shaft to clamp instrument mount assembly along this axis
as did the previous embodiment, instrument mount assembly 220 preferably
utilizes tie pin 240 which is driven in the direction of arrow 245
causing stem grip 226 and clutch member 225 to be forced together to
clamp an instrument delivery stem placed therein and also causing
frustoconical surface 243 of clutch member 225 to forced against
frustoconical surface 244 in mount body 222.

[0165]Tie pin 240 preferably has a generally cylindrical back portion 261
and a front portion which is connected in some manner to stem grip 226.
Preferably, the front portion includes forward extending first and second
flexible prongs 262 and 263. Cylindrical back portion 261 is slidably
received within blind hole 272 of release button 242 and is preferably
biased in the unlocked direction indicated by arrow 270 by compression
spring 247 positioned within blind hole 272 behind tie pin 240.

[0166]Tie pin 240 is preferably driven in the direction of arrow 245 by
the movement of base post 230 which is assembled in the space between
first and second prongs 262 and 263 of tie pin 240. Preferably, base post
230 has an angled cam or ramp 258 that engages back wall 269 at the base
of first and second prongs 262 and 263. As base post 230 is drawn upwards
in the direction of arrow 271 by cam 235 from the open position of FIG.
25 to the closed position of FIG. 24, ramp 258 progressively forces back
wall 269, and thus tie pin 240, in the direction of indicated by arrow
245.

[0167]Tie pin 240, connected at its front end to stem grip 226, locks an
instrument delivery stem in place and locks rotational joint 157 in the
same manner as did threaded shaft 119 of instrument mount assembly 20. In
sum, tie pin 240 urges stem grip 226 towards clutch member 225 and mount
body 222. The movement of stem grip 226, having tang 236 engaged between
upper and lower stem locks 231 and 232 of clutch member 225, closes
together in a clamping fashion surfaces 239 on stem grip 226 and V-shaped
channels 273 on clutch member 225. At the same time, stem grip 226 pushes
against clutch member 225 to force frustoconical surface 243 against
mating frustoconical surface 244 with sufficient force to frictionally
lock the surfaces together, thus preventing relative motion therebetween.

[0168]The operation of cam 235 has been described as generally moving
between an open position, in which the various joints and connections of
instrument mount assembly 220 are free to be easily manipulated about
their respective degrees of freedom, and a closed position in which the
joints and connections resist any relative movement and are thus
effectively locked in position. However, the outer cam profile of cam 235
operating against contact surface 236 may be given a profile that has one
or more intermediate positions such that link pivot 238 is placed at an
intermediate distance from contact surface 236. In an intermediate
position, the joints and connections may be in a stiffened or partially
locked state which allows some positional and orientational manipulation
with somewhat higher operator forces that the completely released
condition. In addition, the action of base post 230 may be such that ball
joint 112 becomes fully locked before tie pin 240 has completely locked
the remaining degrees of freedom. Thus, cam 235 may have a completely
released position where manipulation about all degrees of freedom is
easily accomplished, an intermediate position in which only ball joint
112 is fully locked and the remaining degrees of freedom are unlocked or
may be partially locked, and final closed position in which all degrees
of freedom are locked.

[0169]Instrument mount assembly 220 may optionally be provided with a
release mechanism allowing stem grip 226, and thus the instrument
delivery stem slidably assembled therein, to be released from instrument
mount assembly 220 preferably by activation of release button 242. This
allows instruments associated with instrument mount assembly 15 220 to be
quickly and conveniently removed and replaced or exchanged.

[0170]In a preferred embodiment, first and second prongs 262 and 263 of
tie pin 240 have first and second projections 267 and 268 which
releasably attach tie pin 240 to stem grip 226. Grip housing 274 of stem
grip 226 is covered with a sleeve having a deep counterbore 278 and small
through hole 279. The depth of counterbore 278 is longer than the
exterior of grip housing 274 so as to form internal space 290 (see FIG.
25) when assembled. First and second prongs 262 and 263 can be flexed to
position projections 267 and 268 relatively close together for insertion
through hole 279 where projections 267 and 268 can then expand apart
locking projections 267 and 268 behind surface 280.

[0171]Preferably, projections 267 and 268 have lead-ins 291 and 292 which
urged projections 267 and 268 together as they are advanced through hole
279 so that stem grip 226 can simply be aligned with lead-ins 292 and 292
and then snapped into place without any further action. Alignment of hole
279 is generally quite simply accomplished as the cylindrical exterior
surface 277 of sleeve 260 is slidably received in a substantially coaxial
arrangement within center bore 219 of clutch member 225. Clutch member
225 may optionally have first and second flexures 281 and 282 having
first and second retaining features 283 and 284 so that it may be snapped
in place and thereafter retained within mount body 222.

[0172]As mentioned above, stem grip 226 may be released from tie pin 240.
To separate tie pin 240, it is necessary to flex first and second prongs
262 and 263 together so that projections 267 and 268 will again be
positioned to fit through hole 280. This may be accomplished by providing
a raised portion 264 having a ramp 266 on tie pin 240. A sliding member
may be advanced up tie pin 240 and over ramp 266 and raised portion 264
thus flexing prongs 262 and 263 inwards. Preferably, the sliding member
is a tip portion 289 of release button 242. Tie pin 240 is slidably
received within blind hole 272 of release button 242. The internal
diameter of blind hole 272 is small enough so that when it is advanced
over ramp 266 and/or raised portion 264, prongs 262 and 263 are flexed
inwards. Preferably, the entrance to blind hole 272 has an internal
chamfer 288 so that ramp 266 is smoothly engaged as release button 242 is
advanced.

[0173]Release button 242 preferably has a generally cylindrical body 285
which is slidably received within mating bore 294 (see FIG. 25) of mount
body 222. Release button 242 is retained in place, and its sliding travel
limited, by release button flange 241 on one end and spring clip or
e-clip 293 assembled within e-clip groove 286 on the other end. Spring
material 246, such as a wave spring washer or foam material, may be
disposed between release button flange 241 and mount body 222 to bias
release button 242 outwards. Transverse to blind hole 272 tip portion 289
also has a clearance slot 287 through which base post 230 passes.

[0174]For clarity only, FIGS. 22A-25 have illustrated instrument mount
assembly 220 without hinge member 115 and cam 145 attached. However,
hinge member 115 having rail grip 116 is preferably pivotally mounted,
with cam 145 in place, by way of pins or the like at hinge mount 228 as
described above with reference to instrument mount assembly 20. As
discussed above, cam 145 may be rotated about cam guide 223 using base
lever 122 to secure the instrument mount to a rail or other suitable
structure.

[0175]FIGS. 33-37A illustrate a preferred embodiment of another
alternative instrument mount assembly 400 which allows the assembly to be
locked in a desired position using a single knob. Preferably, the degrees
of freedom available for maneuvering instrument mount 400 is
substantially the same as that of instrument mounts 220 and 20 as
previously discussed. Instrument mount 400 preferably has ball joint
between mount base 421 and mount body 422, a ball or a rotational joint
between mount body 422 and clutch member 425, and a stem hub assembly
which also allows rotation and translation of an instrument delivery stem
held between stem grip 426 and clutch member 425.

[0176]Instrument mount assembly 400 preferably allows the various
articulating or mechanical joints along first axis 481 and second axis
482 to be maneuvered as desired and then locked in a desired position by
actuating or operating a single knob, handle, or other user interface.
Such multiple-axis arrangements are beneficial in many surgical settings
as it is often desirable to have instruments mounted as low as possible
about an access opening into a patient while the instruments themselves
must be maneuvered and secured at sharp angles relative to the access
opening. For example, when securing an instrument for stabilizing the
heart during a CABG procedures, the angle between first axis 481 and
second axis 482 is preferably less than about 120 degrees, more
preferably between about 100 degrees and about 45 degrees, and most
preferably about 90 degrees. Further, the ability to lock joints along
multiple axes with a single knob tends to reduce the operational
complexity of the instrument mount while maintaining the ability to
easily maneuver and secure instruments through an access incision within
a patient. Thus, this configuration provides a low-profile, flexible,
right-angle mount for maneuvering and securing a wide array of surgical
instruments.

[0177]In a preferred embodiment, the ball joint between mount base 421 and
mount body 422 is preferably a ball and socket configuration which may be
created between generally spherical ball 429 provided at the top of mount
base 421 and a mating cavity or socket 440 within mount body 422 adapted
to receive and slide against at least a portion of ball 429. In a
preferred embodiment, the ball and socket configuration may also include
a generally spherical end 432 on base post 430 which couples with mating
surface 447 in the interior of mount base 421. In this configuration,
mount base 421 is controlled between spherical end 432 and socket 440 and
becomes locked in place as the distance between spherical end 432 and
socket 440 is reduced to a dimension which clamps that portion of mount
base 421 residing therebetween.

[0178]The rotational joint between mount body 422 and clutch member 425
may be in the form of a conical clutch formed between frustoconical
surface 423 within mount body 422 and mating frustoconical surface 424 on
clutch member 425. An instrument delivery stem may be clamped in place
within the open space 470 between stem grip 426 and clutch member 425 by
urging stem grip 426 towards clutch member 425. In an alternative
configuration, clutch member 425 may simply be the first link of a
multi-link support member which may have a series of ball and socket
links extending away from said instrument mount and terminating in an end
effector, such as a tissue stabilizer.

[0179]Instrument mount assembly 400 preferably has knob 414, the action of
which to serves not only to operate upon stem grip 426 and clutch member
425 to lock the degrees of freedom along first axis 481 but also urges
spherical end 432 of base post 430 towards socket 440 within mount base
421, thus locking the ball joint along axis 482. Preferably, the locking
action along axis 481 is provided by pull pin 450 which has threaded
section 453 which may be operably engaged by internal threads within knob
414 or any other suitable cam or mechanism configured to deliver the
required axial force to pull pin 450. Pull pin 450 is preferably a
generally rigid member, but may also be a section of wire or cable having
an appropriate threaded end swaged or otherwise attached thereto. For
example, when a multi-link support is coupled to mount body 422 as
discussed above, pull pin 450 may be part of or attached to the proximal
end of the cable used to lock the links of the mufti-link support member.

[0180]In a preferred embodiment, pull pin 450 is secured within grip
housing 441 of stem grip 426. Preferably, pull pin 450 is secured within
grip housing 441 in a manner which does not allow rotation of pull pin
450 within grip housing 441. In a preferred embodiment, pull pin 450 has
knurled section 452 which has an interference fit within bore 442. Grip
housing 441 has a counterbore 444 for receiving head 451 of pull pin 450.
Head 450 bottoms against the end of counterbore 444 allowing grip housing
441 to be pulled against grip housing 441.

[0181]Grip housing 441 of stem grip 426 extends through central bore 420
of clutch member 425. Clutch member 425 is positioned within mount body
422 with frustoconical surface 423 adjacent or against mating
frustoconical surface 424 of mount body 422. When the internal threads
418 of knob 414 are advanced along threaded section 453 of pull pin 450
by rotation of knob 414 in the appropriate direction generally indicated
by arrow 413 about axis 481, head 451 pulls stem grip 426 against clutch
member 425 which is in turn pulled against frustoconical surface 423 of
mount body 422. As knob 414 is tightened in this manner, the frictional
forces at the stem clamping joint and the conical clutch joint increase
in proportion to the axial force delivered by pull pin 450 until the
degrees of freedom begin to stiffen due to the increased frictional
forces and eventually become functionally locked against further relative
motion.

[0182]Base post 430 is generally positioned through internal bore 419 of
mount base 421 such that spherical end 432 abuts mating surface 447
within mount base 421. Preferably, base post 430 (best seen in FIG. 37A)
has an extension or support post 436 which is engaged within a receiving
feature, such as opening 428 at the top of mount body 422. Base post 430
has a transverse bore through which pull pin 450 passes. Base post 430
also has a cam surface 435, preferably supported by or associated with
upper flange 434. Cam surface 435 may be used to close the position of
base post 430 relative to mount body 422 so as to lock the position of
mount body 422 relative to mount base 421.

[0183]Cam surface 435 may be urged upwards generally along second axis 482
by forcing a suitable thrust surface into engagement with cam surface
435. A suitable thrust surface may be urged in the direction indicated by
arrow 483 to contact cam surface 435 causing base post 430 to move
upwards in the general direction indicated by arrow 484. The thrust
surface is generally associated with knob 414 such that advancement or
translation of knob 414 along threaded section 453 of pull pin 450 causes
cam surface to move up or down in relation to the position of the mating
thrust surface. The thrust surface may be integral with knob 414 or as
discussed below provided on a separate element which is engaged by knob
414.

[0185]To eliminate the possibility of the instrument mount assembly
becoming disassembled during use, knob 414 is preferably captured on pull
pin 450. In a preferred embodiment, pull pin 450 has an extension 454
having an enlarged portion 455. Knob 455 is assembled over extension 454
until enlarged portion 455 is forced past restriction 476. Once snapped
in to place, enlarged portion 455 is free to travel within clearance
passage 457 but remains captured by operation of restriction 476 even if
knob 414 becomes completely disengaged from threaded section 453. Knob
414 preferably has a non-threaded internal bore 417 which is sized to
smoothly traverse over both non threaded portions of pull pin 450 as well
as threaded section 453 as may be required over the full travel of guide
housing 416 and knob 414. Knob 414 preferably has one or more grip ridges
411 to facilitate convenient operation by a user, typically wearing
surgical gloves.

[0186]This preferred configuration of instrument mount assembly 400 allows
the mechanism to perform in a number of ways with only slight
modification. For instance, the operation of pull pin 450 and lifter 465
can be configured to have the mechanical joints tighten and lock
according in any desirable order or timing preference. In one embodiment,
the mechanical stem lock, rotating clutch, and ball joint begin to
stiffen generally at the same time. It may be desirable for lifter 465 to
be made from a somewhat softer material or initially have a point or line
contact with cam surface 435 such that lifter 465 deforms or crushes
somewhat as the mechanism is tightened. Lifter 465 may be made from any
suitable tough yet relatively soft engineering plastic such as nylon,
high density polyethylene, polypropylene, or the like. This allows lifter
465 to stiffen the ball joint initially, and then as knob 414 is
tightened further, lifter 465 crushes or deforms so that only modest
increases in frictional forces are imparted to the ball joint while the
remaining mechanical joints along pull pin 450 are allowed to tighten
significantly. Further tightening of knob 414 eventually locks each of
the mechanical joints of instrument mount assembly 400.

[0187]In a preferred embodiment, it is desirable for the ball joint
between mount base 421 and mount body 422 to tighten slightly ahead of
the remainder of the mechanical joints. This allows the user to initially
manipulate mount body 422 to the desired position or orientation and
begin tightening the knob to substantially stiffen or even lock the ball
joint and thus mount body 422. The surgeon may then manipulate the
instrument to the to desired position and orientation using the degrees
of freedom available in the conical clutch and stem clamp. At that point,
knob 414 can be further tightened to lock the remainder of the mechanical
joints. Knob 414 can be loosened slightly to reposition the instrument if
required without disturbing the ball joint. Compression spring 460 may be
used to operate against upper flange 434 to pre-load base post 430
upwardly so that a minimum amount of fictional forces are maintained in
the ball joint between mount base 421 and mount body 422.

[0188]To force base post 430 to clamp at an earlier point as knob 414 is
tightened, the lifter may be constructed of a harder material and may
have a greater contact area against cam surface 435. FIG. 37B illustrates
lifter 490 having a greater contact area for engaging cam surface 435.
Lifter 490 has a more extended profile, and may preferably be square or
substantially square shaped. The extended profile provides the material
for an enlarged surface 492 for contacting cam surface 435. Since lifter
490 is no longer symmetrical about its axis, it may be desirable to key
lifter 490 relative to cam surface 435 to ensure proper alignment.
Preferably, lifter 490 has one or more ribs or protrusions 494 to engage
mating surfaces (not shown) within mount body 422 to ensure surface 492
will be aligned with cam surface 435 as bore 496 rides over pull pin 450.

[0189]Instrument mount 400 may be secured to any stable location such as,
for example, a rib or sternal retractor or other convenient mounting
location which is sufficiently stable to secure the desired instrument.
As with the previous instrument mount embodiments, instrument mount 400
is configured to cooperate with a rail or like structure, preferably
associated with the retractor used to create the access opening through
which an instrument is to be inserted. In a preferred embodiment, hinge
member 412 having rail grip 472 is preferably pivotally mounted to mount
base 421 by way of pins or the like at hinge mount 462 as described above
with reference to instrument mount assembly 20. Cam member 445 may be
rotated about cam guide 438 using base lever 410 causing hinge member 412
to urge rail grip 472 towards rail grip 471 on mount base 421, thus
facilitating instrument mount 400 to be secured to a rail or other
suitable structure.

[0190]The retractor and instrument mounts described above can be used to
mount and stabilize a great number of instruments for use during surgery.
Preferably, the retractor and instrument mounts are used to mount a
mechanical stabilizer for stabilizing at least a portion of the beating
heart during CABG surgery or the like. Described below are a number of
mechanical stabilizer embodiments that are particularly beneficial for
stabilizing the beating heart, especially when used in conjunction with
the retractors and instrument mounts described above.

[0191]Tissue Stabilizers

[0192]Once access to the heart is achieved, and the heart is positioned if
necessary, a means for stabilizing the beating heart is introduced
through the opening created and at least one component of the stabilizing
device of the invention is brought into contact with the beating heart.
The surgeon then applies a stabilizing force to the beating heart via the
stabilizing means which may then be fixed in place by attachment to a
fixed support. When a retractor or platform is fixed in an open position
to expose the heart, the retractor platform may also provide the stable
support structure to which the stabilizing means is affixed. When the
position of the stabilizing means is fixed by attachment to a stable
support or to the retractor platform, the stabilizing force is maintained
for the duration of the procedure.

[0193]The structure of the portion of the stabilizing means which contacts
the heart may include one or more contact members which exert a
stabilizing force on the heart proximate to the site of the anastomosis.
A pair of contact members may be plates or rectangular members which are
placed on either side of the target coronary artery at the site of the
anastomosis and which may have friction means or tissue spreading or
compressing apparatus associated therewith. The contact members may also
be provided by a platform which may be substantially planar or which may
be contoured to fit conformingly on the surface of the heart. The
stabilizing means may also include a delivery system or member which may
have any suitable construction that allows the working end of the
stabilizing means to be positioned and secured as necessary. The delivery
system or member may include flexible multi-link constructions, malleable
constructions or other delivery stem having several alternative
embodiments to facilitate adjusting the position and orientation of the
instrument at the surgical site. For example, the delivery stem may be a
common shaft or alternatively, a curved tubular member, and may have an
adjustable length and the axis of the delivery stem may have at least one
ball joint disposed within its length such that the orientation of the
delivery stem relative to another structure such as the contact members
or stable support may be continuously varied. As is apparent from the
description of the several embodiments, each of the individual
embodiments described and illustrated herein has discrete components and
features which may be readily separated from or combined with the
features of any of the other several embodiments.

[0194]Referring to FIGS. 38-42, a preferred stabilizer assembly for
stabilizing the beating heart is comprised of a foot or base portion 553
attached to a rigid or semi-rigid delivery stem 3, drawn here, for
purposes of example only, as a curved tubular member. Base portion 553
typically has one or more contact members 1 adapted to contact the heart
adjacent the site desired to be stabilized. The contact members 1 may be
substantially planar, may be slightly curved to conform to the shape of
the heart, or may be a non-conforming curve to establish contact between
only a to portion of the contact member 1 and the beating heart. The
shape of the contact members may be varied depending on the clinical
assessment by the surgeon, the design of the other features of the
stabilizing means, or the design of other instruments used to complete
the anastomosis. In some embodiments the contact members 1 may have
apertures, openings or attachments to facilitate connection with sutures
or other devices to achieve the requisite stabilization, occlusion of the
target vessel, or exposure of the target vessel. Examples of suitable
base portions and contact members can be found, for example, in
co-pending U.S. patent application Ser. No. 08/931,158 filed on Sep. 16,
1997, entitled "SURGICAL INSTRUMENTS AND PROCEDURES FOR STABILIZING THE
BEATING HEART DURING CORONARY ARTERY BYPASS GRAFT SURGERY," the entirety
of which is herein incorporated by reference.

[0195]Referring to FIGS. 38 and 39, the proximal end of connecting
delivery stem 3 has handle mechanism 468 assembled thereto which, among
other things, provides the user with a means for locking an end effector
operably attached to the distal end of connecting delivery stem 3. The
mechanism 468 is rotatably secured to the proximal end of the delivery
stem 3 and is formed at a selected angle to the delivery stem to permit a
surgeon to swivel the mechanism to a preferred position where the knob
504 is more readily accessible to allow quickly locking the delivery stem
3 in the orientation selected. In addition, the angled axis of the knob
504 relative to the delivery stem 3 reduces the tendency of the delivery
stem 3 to rotate about its axis when a surgeon applies torque to the knob
504 to lock the associated locking mechanism. The knob 504 is secured to
a screw 539 by suitable means such as press fitting, bonding, etc. Right
and left handle covers 540, 541 comprise the handle 503 and provide the
support for the handle mechanism. When assembled, the covers define
generally a cylinder formed with a selected curvature. A secondary inner
molding, generally indicated at 542, includes various integrally formed
annular walls and shoulders for supporting and containing the knob 504
and screw 539, as well as a cooperating nut 543, and arcuate wedge 544, a
stem retaining ring 545, the proximal end of the delivery stem 3, and a
proximal end of the translatable push rod 505. The proximal end of the
delivery stem 3 includes an annular retaining ring slot 546 which secures
the proximal end of the delivery stem 3 within suitable annular walls in
the corresponding end of the handle covers 540, 541 when the retaining
ring 545, confined by shoulders in the inner molding 542, is snapped into
the slot 546 and the covers are assembled. The nut 543 is confined by
shoulders in the inner molding 542, and the arcuate wedge 544 is slidably
confined by correspondingly arcuate walls 547 also formed in the inner
molding.

[0196]As may be seen, rotation of the threaded screw 539 within the
confined threaded nut 543, causes translation of the screw, pivoting and
thus translation of the translatable wedge 544 which abuts the screw, and
translation of the push rod 505 which abuts the translatable wedge. As is
further described relative to FIGS. 40-42, any tightening or loosening of
the screw 539, however slight, will cause a corresponding translation of
the push rod 505 into or out of the delivery stem 3.

[0197]As depicted in the Figures, the delivery stem 3 and thus the push
rod 505, are formed with a slight arcuate configuration, which permits
additional degrees of freedom and movement and orientation of the distal
end of the delivery stem 3 and thus of the heart contact member 1.
Rotation of the delivery stem 3 about the axis of confinement within the
stem grip 495 or 495a, moves the distal end of the delivery stem 3
through a circular path while changing the angles through which the
contact member 1 can be oriented. This allows a surgeon to conveniently
achieve a wider range of positions and orientations of the contact member
relative to the patient's heart, while keeping the proximal end of the
delivery stem 3 and handle mechanism 468 out of the way as much as
possible.

[0198]FIGS. 40-42 illustrate an associated mechanism for maneuverably
supporting the various embodiments of the contact member 1 and for
cooperatively assisting in the quick locking of the contact member by a
partial rotation of the knob 504 once the member is positioned. To this
end, the distal end of the delivery stem 3 is provided with exterior
threads matching interior threads in a ball/socket 548. The distal end of
ball/socket 548 is provided with slots 549, whereby the remaining
material comprises short extended tips 550 which, when bent in or
inwardly formed, form a socket. A ball/post 551 includes a ball at one
end and a post at the other. When the mechanism is assembled, the
ball/post 551 is inserted into place within the ball/socket 548 with the
ball in the socket and the post protruding from the ball socket. A
mechanism for providing a preloaded source, such as a compression spring
552, is coupled to the ball/socket 548 abutting the ball. The spring 552
is urged by the distal end of the delivery stem 3 to exert a preloaded or
constant minimum force against the ball of the ball/post 551. The post of
the ball/post 551 is solidly fixed as by press fitting, welding, etc., to
the contact member 1. The distal end of the push rod 505 passes through
the spring 552 to abut the ball of the ball/post 551. Thus when the screw
539 is not tightened, the distal end of the push rod 505 exerts a slight
pressure against the ball, however the spring 552 maintains a preloaded
force against the ball sufficient to maintain the contact member 1 at any
orientation set by a surgeon. When the screw 539 is tightened, the push
rod 505 is forced against the ball to prevent any further movement of the
contact member 1. As may be seen, the contact to member 1 can be tilted
to assume many orientations since the narrow center of the post can tilt
into any of the four slots 549 in the ball/socket 548. In addition,
simultaneous rotation of the curved delivery stem 3 provides surgeon with
an even greater variety of orientations of the contact member relative to
a patient's heart.

[0199]The contact member 1 includes a preferred configuration which
improves the size of the area of the heart which is visible to a surgeon
while still providing the required suppression of heart movement
necessary to enable the efficient construction of the anastomosis. More
particularly, the pair of spaced-apart contact members 1 extend from a
common base portion 553, which uniquely first extends back away from the
tips of the, contact members at the point of attachment to the post, as
shown at reference number 554. The spaced contact members 1 then curve
downward away from the common base portion 553 and back past the post and
away from the delivery stem 3. As may be seen in the FIGS. 40-42, the
contact member 1 of this embodiment uniquely is attached to the post on
the same surface as the surface that bears against the surface of the
beating heart. Since the members 1 separate at the base portion 553 at a
point 555 behind the distal end of the delivery stem 3, a surgeon has an
unobstructed and thus optimum view of the heart even below the distal end
of the delivery stem 3.

[0200]The contact members preferably include friction means 556
selectively secured to the bottom surfaces thereof to more securely
engage a beating heart. In addition, the tips of the contact members are
bent upward in the form of "ski tips" to lessen their impact when the
contact members are firmly pressed against a beating heart to suppress
the anastomotic site.

[0201]Although screw means 539/504/543 is illustrated herein as a locking
mechanism to of the handle mechanism 468, it is to be understood that
other mechanisms may be employed. For example, a cam/lever mechanism may
be attached to a rod which in turn imparts a pivoting movement or
translation to a suitable bell crank or pivotable member, which in turn
imparts translation to push rod 505 of the delivery stem 3. Thus, locking
mechanisms other than those specifically described herein may be used.

[0202]The basic configuration as just described with reference to base
portion 553 provides the maneuverability necessary to access and
stabilize any desired vessel on the surface of the beating heart.
However, the exact manner and position in which the stabilizer may be
placed relative to the vessel and the surgical techniques preferred by an
individual surgeon may vary significantly. Accordingly, there is some
potential that certain combinations of stabilizer positioning may
interfere somewhat with the preferred surgical technique of a particular
surgeon. The embodiments illustrated below with respect to FIGS. 43-45B
alleviate any such problems.

[0203]One useful variation, as illustrated in FIG. 43, connects connecting
delivery stem 3 to the base portion of the stabilizer at a position which
is generally offset from the center or off center. Base portion 710 is
again typically formed of a unitary piece of sheet material and has a
curved back portion in which connecting delivery stem 3 is attached to an
extension of the same surface which carries the contacting members,
except that the connecting point 718, to which ball/post 551 is attached
is positioned away from the center and therefore away from the space
between contact members 712 where the anastomosis would be performed.
This configuration tends to ensure that connecting delivery stem 3 will
not interfere with the surgical access to the center area of the base
portion. Of course; the connection to can be offset from the central
region in either direction.

[0204]In addition, base portion 710 illustrates a number of features for
improving the traction and vessel presentation during a CABG procedure on
a beating heart. Contact members 712 of base member 710 have portions 713
having an increased width and which are preferably substantially flat or
slightly curved to conform to the heart. This configuration provides a
larger area for coined regions 715, which represent indentations on the
bottom surface for receiving a traction material, thus providing greater
traction against the surface of the heart.

[0205]Further, base portion 710 provides a smaller open space between
contact members 712. In a preferred embodiment, the spacing 716 between
contact members 712 is less than about 0.350 inches, more preferably less
than about 0.300 inches, and most preferably about 0.25 inches. This
minimized spacing provides stabilization closer to the vessel and, in
some instances, the compressive forces applied through contact members
712 actually tend to present the vessel upwards between contact members
712 in a more favorably pronounced manner. The tip portions 714 of
contact members 712 are angled upwards from the surface of the heart to
minimize any possible trauma to the heart during use.

[0206]As just discussed, the base portions (550 or 710) can be manipulated
or oriented relative to the end of the connecting delivery stem 3 by
virtue of the ball and socket joint between base portion 553 and
connecting delivery stem 3. The amount of angular manipulation or travel
available is somewhat limited as ball/post 551 eventually bottoms out or
stops against either the bottom of slots 549 or extended tips 550. Thus,
the contact members have a limited range of movement relative to
connecting delivery stem 3 based upon the nominal to mounting
relationship between the contact members and the ball/post. Accordingly,
for some procedures, it may be desirable to have a different nominal
relationship between the contact members and the ball/post to delivery
stem connection.

[0207]Referring to FIGS. 44-45B, base member 720 illustrates an
alternative orientation of ball/post 551. Instead of being angled away
from the contact members, base member 720 has a back portion 721 which
allows ball/socket 551 to be mounted generally parallel to contact
members 722. Ball/post 551 preferably extend towards contact members 722
as shown, but may also extend the opposite direction away from the
contact members. The connecting point 723 is preferably offset a distance
724 from the central area between the contact members 722. The connecting
point 723 is also off set a greater distance 726 from the contacting
place of contact members 722. In nominal position of base portion 722
relative to ball/post 551, this configuration tends to keep the
connecting delivery stem 3 clear from the central portion between contact
members 722. Furthermore, relative to connecting delivery stem 3, contact
members 722 can be maneuvered through a range of motion different from
base member 553 due to the initial orientation of ball/post 551.

[0208]Because the preferred location of the attachment of the connecting
delivery stem 3 to the base portion may be different from surgeon to
surgeon and from procedure to procedure, it may be desirable to have the
ball/post moveable to more than one location. In one embodiment shown in
FIG. 46, for example, ball/post 562 has threaded end 561 which may be
threaded into any desired threaded receiving hole 563 provided in
stabilizer base 560. Ball post 564 is preferably provided with one or
more flats 564 on the exterior thereof to facilitate tightening or
loosening of the threaded connection. In the embodiment shown, stabilizer
base 560 has threaded receiving holes 563 to provide center, offset
right, and offset left connecting positions.

[0209]Referring to FIGS. 47 and 48, ball/post 572 may be captured within
slot 571 formed in stabilizer base 570. Slot 571 preferably has two or
more positions where the ball/post can be positively locked. In a
preferred embodiment, slot 571 preferably has two or more key-hole
openings 573. Key openings 573 are sized to receive first post portion
577 having an outside diameter which closely matches the inside dimension
of key opening 573. First post portion 577 of ball/post 572 is released
from key hole 573 by pulling ball post in the direction indicated by
arrow 579 until second post portion 578 is positioned within keyhole 573.
Second post portion 578 is sized to have an outside diameter small enough
to fit arid traverse through slot 571. Ball/post 572 may then be
traversed along the path defined by slot 571 until the next desired key
hole is reached, which may then be engaged by first post portion 577 to
secure ball/post 572 in position on stabilizer base 570.

[0210]First post portion 577 may be kept in engagement with keyholes 573
by any, convenient manner. For example, ball/post 572 may be spring
biased in the locked position between upper flange 574 and lower flange
575, preferably using spring washers 576 as shown. Ball/post 572 may also
be locked into operating position within keyholes 573 by using a
retaining or locking clip, such as locking clip 580 illustrated with
reference to FIGS. 49 and 50. Locking clip 580 has slot 584 adapted to
slide over second post portion 578. Locking clip 580 includes a thin
portion 585, a thick portion 583, a transition ramp 582 between thin
portion 585 and thick portion 583, and a grip or handle portion 581. With
locking clip 580 in the open position shown in FIG. 44, ball to post 572
is free to move upwards in the direction of arrow 579, thus releasing
first post portion 577 from key hole 573. When locking clip 580 is moved
in the direction indicated by arrow 586, the outer thickness of thick
portion 583 is wedged between lower flange 575 and stabilizer base 570,
thus locking ball/post 572 in place within keyhole 573.

[0211]Stabilizer base 590 in FIG. 51 has ball/post 592 mounted to an
articulating member which is moveable between two or more positions.
Preferably, ball/post 592 is mounted on first end 594 of pivoting link
591 which is pivotably attached to stabilizer base 590 at pivot pin 596.
Preferably, pivot pin 596 is centrally located on pivoting link 591. At
second end 593 of pivoting link 591, a locking knob 595 may be provided
to engage stabilizer base 590. Preferably, locking knob 595 has a
threaded shaft or other such fastening or locking feature which engages
mating threaded holes (typically one positioned under locking knob 595
and one under ball/post 592) in stabilizer base 590. The ball/post 592
and locking knob 595 are preferably spaced equal distances from pivot pin
596 such that when pivoting link 591 is rotated as indicated by, arrow
597, the position of ball/post 592 and locking knob 595 are reversed.

[0212]Another embodiment of a tissue stabilizer having an adjustable
attachment position of the delivery stem is illustrated in FIGS. 52-55.
Stabilizer base assembly 625 includes top member 605 and stabilizer base
600, having contact members 606 and 607 and notch or relief 603 under
which a vessel may safely pass without being occluded. At least a portion
of stabilizer base 600 has outer profile 601 which is generally curved or
circular at a predetermined radius. Top member 605 has a mating interior
curvature such that stabilizer base 600 and top member 605 concentrically
rotate relative to each other, preferably about a common center point.
Ball/post 602 may be attached at a convenient position, typically
centered, on top member 605. Rotation of top member 605 relative to
stabilizer base 600, as indicated by arrows 620 and 619, thus adjusts the
position of ball/post 602 along an arcuate path relative to contact
members 606 and 607.

[0213]To facilitate the secure attachment and smooth rotation of top
member 605 relative to stabilizer base 600, top member 605 may be
provided with one or more projections adapted to be received within guide
slots provided in stabilizer base 600. In a preferred embodiment, top
member 605 has side projections or rails 608 and 609 which snap into
lower slots or channels 611 and 610 in stabilizer base 600 as top member
605 is urged into a concentric position over stabilizer base 600. Rails
608 and 609 slide within channel 611 and 610 to maintain a secure
attachment and controlled rotation of top member 605 and stabilizer base
600. Top member 605 may optionally have tab 612 adapted to be received
within upper slot 604 on stabilizer base 600. Upper slot 604 may have a
plurality of detents or teeth which form a desired number of detented
positions as tab 612 is rotated around the path of upper slot 604. In a
preferred embodiment, detented position 617 is formed between tooth 613
and slot end 616 and detented position 618 is formed between tooth 614
and tooth 615. Of course, detented positions may be created at any
desired location using a variety of alternate constructions. Preferably,
the detent action of tab 612 allows the operator to manually select a
position of ball/post 602, but then holds the position of top member 605
relative to stabilizer base 600 against movement during use to ensure
effective stabilization of a target vessel on the beating heart.

[0214]In addition to the critical function of stabilizing the beating
heart, it is also important for the tissue stabilizer to present the
stabilized coronary artery in a manner which allows sutures to be easily
placed around the mouth of the arteriotomy as required to create the
anastomosis. FIGS. 56A-59 illustrate a tissue stabilizer embodiment
involving a base portion having a single contacting surface for
stabilizing a target vessel on the beating heart and a mechanical bail
element to facilitate optimal vessel presentation.

[0215]Referring to FIGS. 56A and 56B stabilizer base 740 is shown attached
to delivery stem 3 using ball/post 730. Delivery stem 3 is shown
connected generally to the center of stabilizer base 740 at approximately
a right angle, however, as discussed above, the ball/post 730 could be
connected at any desired offset or orientation or the position of
ball/post 730 could be adjustable. Stabilizer base 740 preferably has a
single contacting surface 742 which may be flat or curved to at least
partially conform to the surface of the heart. Contacting surface 742 is
sized to provide sufficient contacting area such that sufficient
compressive force can be applied to the beating heart to achieve
effective immobilization or stabilization of a target coronary artery.

[0216]Stabilizer base 740 preferably has an extending frame member or bail
745 attached thereto. Bail 745 may be a thin, round or square
cross-sectioned member, and is preferably a stainless steel wire. Bail
740 has a bail portion 756 which is generally parallel to stabilizer base
740 and may have relieved sections 747 formed therein so as not to
occlude the vessel during use. Bail portion 756 may have tissue gripping
features, such as teeth 755. In an optional embodiment, bail portion 756
may be provided with rotating cover or a spiral wound thread (not shown)
so that bail portion may be more easily repositioned, under a stabilizing
load, over the surface of the heart as discussed below.

[0217]In a preferred embodiment, bail 745 is moveable relative to
stabilizer base 740. Bail 745 can, be moved in or out in the direction
indicated by arrow 750 to cause bail section 756, which is generally
parallel with stabilizer base 740, to compress tissue towards stabilizer
base 740 or stretch tissue away from stabilizer base 740. Thus, bail 745
can be moved in and out to compress or stretch the tissue surrounding a
coronary artery until the optimum presentation for performing the
anastomosis is achieved. The generally parallel portion may be vertically
offset from contacting surface 742 by a distance 757 which is typically
about 0.050 inches to about 0.200 inches.

[0218]Although bail 745 may be attached in a number of ways, bail 745 is
preferably formed with first and second end portions 748 and 749 having
detents or teeth 746. Stabilizer base 740 preferably has channels 751 and
752 for receiving end portions 749 and 748 respectively. Channels 751 and
752 preferably have internal mating teeth 753 for engaging teeth 746. End
portions 748 and 749 can be incrementally advanced into channels 752 and
751 as teeth 746 deflect and release from a mated position relative to
teeth 753 and then successively engage the next mated position.
Stabilizer base 740 may include cover 754 over channels 751 and 752. So
that the stabilizer can be removed from around a completed anastomosis,
at least one end of bail 745 is detachable from stabilizer base 740. In a
preferred embodiment, stabilizer base 740 is substantially symmetrical
allowing bail 745 to be assembled from either side in a right or left
handed configuration.

[0219]Bail 745 is preferably flexible or semi-flexible relative to
stabilizer base 740. As a result of its inherent flexibility, bail 745
applies a predetermined force against the heart that, under operating
conditions, may be generally independent of the stabilizing force applied
to stabilizer base 740 to stabilize the beating heart. That is, once
stabilizer base 740 is forced against the surface of the heart, the force
applied by bail 745 is a function of its mechanical spring rate relative
to stabilizer base 740.

[0220]FIGS. 57A and 57B illustrate another single contact stabilizer base
having a bail 762 which is secured at only one end. Stabilizer base 760
may have a housing 765 having a series of internal teeth (not shown).
Bail 762 has a toothed end 766 which is received within housing 765 to
engage with the mating teeth provided therein. As with the embodiment
above, bail 762 has a generally parallel portion 763 which is moveable
relative to stabilizer base 760 in the direction generally indicated by
arrow 767 to stretch or compress the surrounding tissue for optimum
vessel presentation. Bail 762 may have tab 761 to facilitate grasping by
an instrument, such as for example forceps 761. The free end 764 of bail
762 is preferably rounded or somewhat bulbous so as to be a traumatic.
Because bail 762 attaches only at one end, the stabilizer can be easily
removed from the completed anastomosis without removing bail 762 from
stabilizer base 760.

[0221]In another embodiment of the stabilizer, the wire frame member or
bail may have a drive mechanism for moving the bail relative to the
stabilizer base. Referring to FIG. 58 stabilizer base 770 has housing 771
which is constructed with guide channel 774 having gear 775 mounted for
rotation therein. Bail 772 has a toothed end 773 which may be assembled
within guide channel 774 such that rotation of gear 775 causes bail 772
to be moved in and out in the direction indicated by arrow 43. Gear 775
may be driven by any suitable tool, for example, gear 775 may have a
drive hole 778 for engagement by a suitable drive tool 771.

[0222]Another driven bail stabilizer is shown in FIG. 59. In this
embodiment, stabilizer base 780 has threaded shaft 781 preferably
supported at its end portions by bushings or bearings 783 and 784. One
end of the threaded shaft is connected to a flexible drive 785 through a
flexible or universal joint 791. The flexible drive may be routed up
delivery stem 3. Preferably flexible drive 785 is secured to delivery
stem 3 by way of a thin polymeric coating. Bail 782 is connected to
threaded collar 787 which cooperates with threaded shaft 781 to move bail
in and out relative to stabilizer base 780 in the general direction
indicated by arrow 790. The screw and collar drive mechanism is
preferably concealed by housing 788 which has only a small slotted
opening 786 allowing passage of bail 782.

[0223]With each of the flexible bail embodiments described above,
stabilization and vessel presentation are relatively independent. First,
the beating heart is typically stabilized using a compressive force
delivered by way of the single contacting surface provided by the
stabilizer base. The bail may then be manipulated in or out to obtain the
optimum presentation of the vessel for whatever surgical-procedure is
underway. For example, one bail position may be optimal for creating the
arteriotomy, another bail position for insertion of a shunt or like
device (should one be used), another bail position for creating the
anastomosis, and so on. All the while, the stabilization of the beating
heart itself remains optimized by the contacting surface of the
stabilizer base.

[0224]The Stabilization System

[0225]Preferred embodiments for each of the retractor, the instrument
mount and the tissue stabilizers have been discussed in detail above.
While each component may be utilized separately, superior access and
stabilization can be achieved when the multiple components are used
together for performing a minimally invasive cardiac surgery, preferably
through a sternotomy approach. Referring to FIG. 60, retractor assembly
900, including drive mechanism 910 and first and second platform blades
915 and 920, may be used to spread the sternum, providing access and
direct visualization to the thoracic cavity. Retractor assembly 900 also
allows sutures to be fixed or organized. Stabilizer assembly 800 isolates
and provides local immobilization of the target vessel on the beating
heart. Instrument mount assembly 850 facilitates precise maneuvering of
the stabilizer and ensures a stable, motion free mount at the desired
position and orientation.

[0226]To begin a typical beating heart CABG procedure using the preferred
stabilization system illustrated in FIG. 60, drive mechanism 910 is
preferably placed in the fully closed position with moveable housing 925
positioned against or adjacent fixed housing 930. First platform blade
915 is then assembled to moveable housing 925 and a second platform blade
920 is assembled to fixed housing 930. After ensuring that platform
blades 915 and 920 are fully and securely attached to drive mechanism
910, engaging members 935 of platform blades 915 and 920 are securely
seated on the incised sternum created using standard surgical procedures.
Drive handle 940 may then be rotated clockwise to separate platform
blades 915 and 920, thus creating the desired opening for accessing the
beating heart.

[0227]If the heart is positioned using sutures, the sutures may be placed
through the tissue at the desired location and secured to platform blades
915 and 920. Sutures 945 may be slid into suture holder slots 950 to
engage the suture. To ensure proper a proper hold, only one suture strand
is preferably engaged within each suture holder slot 950. Sutures 945 are
released from platform blades 915 and 920 by concurrently pulling back
and up on suture 945 while pulling the suture through the suture holder
slot 950.

[0228]With the heart positioned as desired, instrument mount assembly 850
may be assembled to platform blade 920 (or 915) by hooking stabilizer
mount base 955 onto rail 960 (or 961) at the desired location and moving
the base lever (not visible in this view) clockwise to the closed
position to secure instrument mount assembly 850 onto rail 960. Mount
body 110 may be oriented to the desired angle by way of ball joint 965
and locked into place by turning the top mount knob 855 clockwise.

[0229]Stabilizer base 810, having contact members 812 and 814, may then be
positioned on the epicardium of the beating heart by gently lowering
delivery stem 820 using one hand to guide stabilizer base 810 onto the
target area on the heart. Incremental pressure is applied to stabilizer
base 810 situated on the epicardium until the desired immobilization, or
stabilization is achieved. Delivery stem 820 is secured in the desired
position by turning side mount knob 860 clockwise and stabilizer base 810
is secured in the desired position relative to delivery stem 820 by
turning the stabilizer stem knob 830 clockwise. With the beating heart
stabilized, the anastomosis, or other desired procedure, is completed.

[0230]To remove stabilizer base 810, delivery stem 820 is held with one
hand while side mount knob 860 is loosened with other hand. Stabilizer
base 810 is then carefully removed from the anastomotic site. The base
lever is moved to the open position to release instrument mount assembly
850, and stabilizer assembly 800 mounted thereto, from rail 960 on
platform blade 920. When the entire bypass procedure is completed, drive
handle 940 is rotated in the counter clockwise direction to close drive
mechanism 910 and platform blades 915 and 920. Retractor assembly 900 may
then be gently removed from the access incision. To remove platform
blades 915 and 920 from moveable housing 925 and fixed housing 930,
respectively, release latches 970 are manually activated and platform
blades 915 and 920 may be pulled generally straight away from Drive
mechanism 910. Drive mechanism 910 may then be sterilized and prepared
for use in a subsequent procedure.

[0231]While certain embodiments are illustrated in the drawings and have
just been described herein, it will be apparent to those skilled in the
art that many modifications can be made to the embodiments without
departing from the inventive concepts described. For purposes of
illustration only, the principles of the present invention has been
generally described with reference to a coronary artery bypass procedure,
but may readily be applied to other types surgical procedures not
specifically described. Many other uses are well-known in the art, and
the concepts described herein are equally applicable to those other uses.
Further, the different components of the various exemplar embodiments
described above can be combined in any desirable construction.
Accordingly, the invention is not to be restricted except by the claims
which follow.

Patent applications by Charles S. Taylor, San Francisco, CA US

Patent applications by David J. Paul, Scotts Valley, CA US

Patent applications by Eugene Edward Reis, San Jose, CA US

Patent applications by Gary B. Weller, Los Gatos, CA US

Patent applications by Harry Leonard Green, Ii, Santa Cruz, CA US

Patent applications in class With special blade or retracting surface structure

Patent applications in all subclasses With special blade or retracting surface structure